DHK: pubs: DNA Emerging Issues WLR 01

Abstract: DNA typing has had a major impact on the criminal justice system. There are hundreds of opinions and thousands of cases dealing with DNA evidence. Yet, at virtually every stage of the process, there are important issues that are just emerging or that have been neglected. At the investigative stage, courts have barely begun to focus on the legal limitations on the power of the police to obtain samples directly from suspects and to use the data from DNA samples in various ways. Issues such as the propriety of "DNA dragnets" (in which large numbers of individuals in a geographic area are asked to provide samples voluntarily), the validity of court orders for samples based on a lesser standard than probable cause, and the permissibility of collecting DNA "abandoned" in public places are being litigated for the first time. Using crime-scene samples to infer racial or ethnic characteristics is emerging as a distinct possibility. Then there are the more than 282 million specimens of human biological material stored by private and public agencies in the United States; in some situations, police may well turn to some of these repositories to obtain samples. There is little or no case law analyzing the constitutional restrictions on these investigative practices.

After the filing of charges, an accused sometimes moves to dismiss on the ground of the expiration of the statute of limitations. However, there is a movement to carve out a DNA exception to the statute of limitations in cases in which DNA evidence permits the identification of the perpetrator after the expiration of the normal period of limitations. The argument is that the legislative purpose of the statute is to prevent the maintenance of prosecutions based on stale, unreliable evidence but that DNA evidence is so reliable that its availability should lift the bar of the statute. However, little attention has been given to the difficulties inherent in drafting such a legislative exception that will not be overinclusive.

At the trial stage, in a growing number of cases, after the defense attacks the weight of the government's DNA evidence, prosecutors are commenting to the jury that the defense has requested an opportunity to retest the DNA. Do such comments run afoul of the Fifth or Sixth Amendment?

The purpose of this Article is to identify and analyze such emerging issues. If the criminal justice system is to realize the full potential of DNA technology while maintaining the essential fairness of the system, it must come to grips with these issues in short order.

Fifteen years ago, deoxyribonucleic acid (DNA) analysis began to be applied to law enforcement. 1 Before long, its suitability for the

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courtroom was bitterly contested. Significant questions were raised in the popular press, 2 books from scientific publishers, 3 law reviews, 4 and, of course, in trial and appellate courts. 5 Today, the controversy over the scientific validity of forensic DNA testing has largely dissipated, 6 but more subtle issues of criminal procedure and evidence often arise when DNA is employed in the investigations and trials. Unlike the question of the scientific validity of the usual methods of forensic DNA analysis, many of these new matters have yet to be extensively litigated. This Article identifies some of these emerging or neglected issues. 7

Part I discusses constitutional problems that arise when the government uses DNA evidence in investigating a crime. It focuses primarily on methods of acquiring DNA from an individual suspected of committing a crime and considers the constitutionality of compelling suspects to submit to DNA sampling and of acquiring stored samples of a suspect's DNA or medical records relating to these samples from private medical providers or laboratories. 8 It also considers the constitutionality of gathering DNA from large numbers of people to see whether any have genotypes that match those seen in the trace evidence. It shows that although the Fourth Amendment usually requires the police to have probable cause and a warrant to compel a person to provide a DNA sample, there are many situations in which police may be able to secure DNA samples without these safeguards.

Part I also considers a second investigative use of DNA: deducing physical or other characteristics of an individual whose DNA is found at the scene of crime. Genetic typing will permit inferences as to ancestry, physiognomy, or inherited disorders. Part I concludes that investigators can use genetic data to make valid inferences without infringing any constitutional rights.

Part II addresses legal issues that arise at a later stage in the justice system, when DNA analysis is used as evidence in the prosecution of persons charged with crimes. It discusses the admissibility of new DNA tests and the results of proficiency tests at particular laboratories and suggests that the rules of character evidence create a largely unrecognized, and probably undesirable, obstacle to admissibility. It also considers proposals that the durability of DNA evidence justifies extending the statute of limitations for prosecutions for certain crimes. It calls for more legislative sensitivity to the policies that underlie

limitations on the period of criminal liability and a better understanding of how the durability of DNA evidence interacts with these policies.

For some of these emerging issues, it is possible to make a reasonably confident prediction of the courts' ultimate resolution of the questions posed by DNA technology. However, other questions seem much closer and require more attention to the underlying policies. The hope is that this Article will stimulate judicial attention and scholarly commentary by identifying the full range of issues and analyzing some of the unresolved questions surrounding the use of DNA evidence.

Traditionally, DNA has been employed to link a suspect to a crime. Finding that a suspect's DNA matches the DNA left at a crime scene, for example, tends to incriminate the suspect. 9 Inversely, when the DNA does not match, the suspect usually can be excluded as the source of the crime-scene DNA. 10 If trace evidence is to be used in these ways, the police must secure samples of DNA from individuals who might have committed the crime under investigation. Officials can secure such samples in many ways. They can seek a court order to compel an individual to submit to sampling; they can turn to a preexisting collection of DNA samples; they can take a sample with the consent of the individual; or they can try to locate a sample that the suspect has abandoned.

As a matter of constitutional law, the principal constraint 11 on such government action is the Search and Seizure Clause of the Fourth Amendment to the U.S. Constitution, 12 which states:

However, what makes a search reasonable and when a warrant supported by probable cause is required are not always apparent. The following sections analyze the application of these requirements to the various methods of acquiring DNA from suspects.

Because the Search and Seizure Clause protects "[t]he right of the people to be secure in their persons," it applies both to restraining a person and to searching the inside or outside of a person's body. The Supreme Court made this clear in Schmerber v. California. 14 Schmerber was arrested at a hospital while receiving treatment for injuries suffered in an automobile accident. He had allegedly been driving while intoxicated, and a police officer directed a physician at the hospital to withdraw a blood sample. 15 Chemical analysis revealed a high concentration of alcohol in his blood at the time of the offense, and the report of this analysis was admitted in evidence at trial in Los Angeles Municipal Court even though the defendant objected that he never consented to the test. 16 He was convicted of driving an automobile while under the influence of intoxicating liquor, and the state appellate court affirmed the conviction. 17 The U.S. Supreme Court affirmed, but only

after applying the Search and Seizure Clause to the act of removing the biological sample. 18 The majority began its analysis from the premise that "[s]uch testing procedures plainly constitute searches of 'persons,' and depend antecedently upon seizures of 'persons' . . . within the meaning of that Amendment." 19 The Court emphasized that "[t] he integrity of an individual's person is a cherished value of our society." 20

Because Schmerber established that the Fourth Amendment applies to removing material from a suspect's body, as a general rule, police must persuade a judge or magistrate that there is probable cause to believe that the desired DNA sample will produce evidence linking the suspect to the crime. 21 With judicial authorization, police can use necessary force to extract the biological material. 22 Furthermore, once the authorities legally have acquired a suspect's profile, they are permitted to compare it to profiles from unrelated, unsolved crime-scene stains. 23 The current state of the law appears to allow evidence legitimately acquired for one purpose to be used for another purpose, at least if the additional use entails no further search or seizure of the person. 24

In some circumstances, however, either a warrant or probable cause might not be essential to obtain the sample in the first place. For instance, if a person is legitimately under arrest, the seizure of the person is justified, 25 and routine, non-invasive DNA sampling of all arrestees solely for the purpose of creating a record of the true identity of the individual is probably constitutional. 26 Furthermore, according to conventional wisdom, once the government has acquired the sample

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consistent with Fourth Amendment protections, the Search and Seizure Clause does not bar its use for another purpose. 27

It also is likely that an order compelling a person to give a sample could be issued on something less than probable cause. In Davis v. Mississippi, 28 the Supreme Court suggested in dictum such a procedure. A woman in Meridian, Mississippi, reported that "a Negro youth" broke into her home and raped her. Police, "without warrants, took at least 24 Negro youths," including Davis, "to police headquarters where they were questioned briefly, fingerprinted, and released without charge." 29 After Davis's fingerprints were discovered to match those lifted from the windowsill, he was indicted, tried, and convicted. 30 His objection to the admission of the fingerprint evidence was overruled, and the Mississippi Supreme Court affirmed the conviction on the theory that fingerprint evidence is so reliable that the Fourth Amendment exclusionary rule does not apply to this evidence. 31 The U.S. Supreme Court reversed. The Court held that the Fourth Amendment requires the exclusion of evidence that is the fruit of an unreasonable search or seizure, regardless of how reliable that evidence may be. 32 Reasoning that Davis was detained without a warrant and without probable cause, and that he was not merely fingerprinted but interrogated, the Court concluded that the resulting fingerprints were inadmissible. 33 However, the Court's response to the state's argument that an arrest made solely for the purpose of obtaining fingerprints should be allowed without probable cause was less definitive. Although Justice Brennan, writing for the

majority of the Court, emphasized that "[d]etentions for the sole purpose of obtaining fingerprints are . . . subject to the constraints of the Fourth Amendment," 34 he added that:

The Court opened the door to the possibility that "the requirements of the Fourth Amendment could be met by narrowly circumscribed procedures for obtaining, during the course of a criminal investigation, the fingerprints ofindividuals for whom there is no probable cause to arrest." 36 The Court virtually invited states to devise procedures to obtain evidence of identifying characteristics on the basis of something less than probable cause.

Many states seized on this invitation by adopting statutes or court rules permitting the police to obtain evidence of identifying physical characteristics after a showing of founded or reasonable suspicion. 37 For instance, Arizona authorizes magistrates to issue "an order authorizing . . . temporary detention, for the purpose of obtaining evidence of identifying physical characteristics" on a showing of "[r]easonable cause

for belief that a felony has been committed" and proof that the "physical characteristics . . . may contribute to the identification of the individual who committed such offense." 38 As in this instance, 39 the language of many of these statutes and court rules is broad enough to apply to DNA samples. 40

One might argue that these statutes or rules are too broad--that unlike the fingerprints in Davis, blood, urine, or hair samples should be treated differently because they have the potential to reveal information that is more significant than the pattern of whorls and ridges in a fingerprint. Some support for this distinction can be found in Skinner v. Railway Labor Executives' Ass'n, 41 which involved drug testing of railway employees. The Court observed that "chemical analysis of urine, like that of blood, can reveal a host of private medical facts about an employee, including whether he or she is epileptic, pregnant, or diabetic." 42 The same concern with "private medical facts" arises with

any samples that can be subjected to DNA analysis. To this extent, it would be facile to say that DNA typing, like the fingerprinting in Davis, "involves none of the probing into an individual's private life and thoughts that marks an interrogation or search." 43 Certain parts of one's genome--those that are related to otherwise nonobvious disease states or behavioral characteristics--are as much, if not more, a part of "an individual's private life" as are the hormones or other chemicals found in one's urine.

However, all the other factors listed in the Davis dictum apply to DNA sampling. Detention to obtain the sample cannot "be employed repeatedly to harass an individual, since the police need only one set of each person's [DNA types]." 44 DNA analysis "is an inherently more reliable and effective crime-solving tool than eyewitness identifications or confessions." 45 And, "the limited detention need not come unexpectedly or at an inconvenient time." 46 Moreover, in describing these features of fingerprinting, the Davis Court recognized the possibility that the police might abuse even fingerprinting to harass or inconvenience a suspect. 47 The suggestion of relaxing the probable cause requirement presupposes the police will conform to the court order and the judiciary will issue orders that avoid these problems. This premise applies as well to the informational privacy concern voiced in Skinner. Just as there is no need to detain an individual repeatedly or to detain a person in the middle of the night, there is no reason for the police to probe parts of the genome that conceivably could be used to indicate disease states, susceptibilities, or the like. 48 Because the judicial order can limit the search to loci that are of strictly biometric interest, the analogy to Davis is apt. Detention for DNA typing, as much as detention for fingerprinting, "may constitute a much less serious intrusion upon personal security than other types of police searches and detentions." 49 If a person can be compelled to submit to fingerprinting on reasonable

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suspicion rather than probable cause, he or she can be required to submit to DNA sampling on the same showing. 50

B. Legality of Acquiring Samples or Records from Medical Providers or Laboratories

Rather than compel a person to submit to DNA sampling, police might obtain DNA data on a suspect from preexisting samples or data-bases. As of 1998, it was estimated that there were more than 282 million specimens of human biological material stored in the United States, with samples from another 20 million individuals accumulating each year. 51 These samples are stored in academically based repositories of scientists studying genetic disorders, commercially based repositories that offer DNA banking as a service to researchers and individuals, teaching and other hospitals that have acquired samples in the course of clinical diagnostic or surgical procedures, laboratories that screen blood samples of newborns for metabolic or other diseases pursuant to state public health laws, and armed forces repositories of pathology specimens and samples collected to permit identification of human remains. 52 Although the Fourth Amendment plainly regulates police

efforts to obtain samples directly from suspects, 53 the prohibition against unreasonable searches applies only to government action. 54 As the Supreme Court commented in United States v. Jacobsen: 55 "This Court has . . . consistently construed this protection as proscribing only governmental action; it is wholly inapplicable 'to a search or seizure, even an unreasonable one, effected by a private individual not acting as an agent of the Government or with the participation or knowledge of any governmental official.' " 56

This state action doctrine raises the possibility that police may be able to acquire preexisting information from cooperative private hospitals or laboratories without a court order and without probable cause or reasonable suspicion. 57 This practice would fall outside the constraints of the Fourth Amendment on two conditions: (1) the government did not instigate the original acquisition of the data, and (2) in acquiring the data that the suspect already has provided private entities, the state is not engaging in any search or seizure.

The first condition is relatively straightforward and often will be satisfied for medical records and tissue samples. 58 Pathology specimens at private hospitals, for example, would fall into this category, but newborn screening samples compelled under state law would not.

The second condition is more subtle, for it depends on the meaning given to the phrase "search or seizure." The basic framework for determining whether a form of data collection amounts to a search or seizure for Fourth Amendment purposes is found in Katz v. United States. 59 In Katz, the government acquired key evidence to convict the defendant of interstate gambling by attaching an electronic listening-and-recording device to the outside of a public telephone booth. The government argued that the interception was not a search because there was no physical trespass and the telephone booth was a public place. 60 The Supreme Court held that neither entry onto private property nor inspection of tangible items is an essential feature of a search, for "the Fourth Amendment protects people, not places." 61 The Fourth Amendment protected the defendant, the Court explained, because "a person in a telephone booth . . . who occupies it, shuts the door behind him, and pays the toll that permits him to place a call is surely entitled to assume that the words he utters into the mouthpiece will not be broadcast to the world." 62 Because the federal agents had no warrant authorizing the interception, the Court held that the search violated the Fourth Amendment. 63 In a concurring opinion, Justice Harlan elaborated on the majority's remarks. In perhaps the most famous passage in the Katz opinions, he wrote: "[T]here is a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as 'reasonable." ' 64 Applying this standard, he explained that "[t]he point is not that the booth is 'accessible to the public' at other times, but that it is

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a temporarily private place whose momentary occupants' expectations of freedom from intrusion are recognized as reasonable." 65

Although the courts have applied the Katz "test" in many contexts, for present purposes the most important is the Supreme Court's 1976 decision in United States v. Miller. 66 In Miller, the accused was charged with possessing an unregistered still, carrying on a distillery business without paying the whiskey tax, and possessing whiskey on which no taxes had been paid. 67 Prior to trial, the government served subpoenas on two banks at which the defendant had accounts. The banks surrendered copies of the defendant's checks and deposit slips as well as the bank's own records of the defendant's accounts. The defendant moved to suppress the documents, but the trial judge denied the motion and admitted the evidence at trial. 68 The defendant was convicted and later appealed. The First Circuit reversed, holding that the banks' surrender of the records violated the defendant's Fourth Amendment rights. 69

On appeal, the Supreme Court reversed the First Circuit's decision and reinstated the defendant's conviction. Writing for the majority, Justice Powell relied heavily on Katz. The Court upheld the denial of the suppression motion because "there was no intrusion into any area in which [the defendant] had a protected Fourth Amendment interest." 70 Because the defendant had transferred the checks and deposit slips to the bank, he could not assert "ownership []or possession" as to any of the subpoenaed records, 71 and "[a]ll of the documents obtained, including financial statements and deposit slips, contain only information voluntarily conveyed to the banks and exposed to their employees in the ordinary course of business." 72

The defendant had argued that he retained an expectation of privacy because he had made the information available to the bank only "for a limited purpose." 73 However, Justice Powell made short shrift of that argument:

The logic of Miller has been applied to medical samples or records. As in the case of financial information, the patient or research subject neither owns nor possesses tissue samples or data that have been "voluntarily conveyed" to health care providers or medical researchers. Thus, in many of the cases challenging police requests for medical samples and records, the lower courts invoke Miller to defeat the defendant's claim. 76

Nevertheless, Miller might be distinguished on at least three bases. First, the Miller Court stated that the bank records in question concerned "commercial transactions." 77 In contrast, a medical record can relate to far more intimate aspects of a person's life, 78 and the law should not create significant disincentives to persons seeking necessary medical advice and treatment. Although a patient has a greater privacy interest in medical records than a business or individual has in bank records, 79 it is not clear that the interest is so much deeper that the two types of records are distinguishable when the prosecution seeks the records to advance a criminal investigation. 80 Although recent polls indicate that the vast majority of Americans are concerned about the privacy of their medical records, 81 there are countervailing indications of the relevant, societally recognized expectations of privacy that are firmly settled. Most juris-dictions have enacted a general physician-patient privilege, 82 which typically encompasses not only communications in a conventional sense, but also any information that the physician gains by virtue of the examination. 83 Yet, the majority of jurisdictions do not recognize the privilege in criminal cases. 84 Thus, several courts have pointed to that

limitation as evidence that society is unwilling to recognize a constitutionally enforceable privacy expectation in medical records or samples. In Thurman v. State, 85 for instance, the Texas Court of Appeals pointed out that the medical privilege is inapplicable to criminal cases; 86 hence, even if the citizen has a subjective expectation of privacy, society does not recognize that expectation as reasonable in a criminal setting. 87 For that matter, many jurisdictions not only carve out an exception to the privilege for criminal proceedings, but also require physicians to report certain types of events such as violent injuries and child abuse to the public authorities. 88 One jurisdiction has enacted even more sweeping legislation, requiring hospitals to furnish blood-test results to the prosecutor on request in a criminal investigation. 89 The reporting requirements and limited scope of the medical privilege strongly suggest that the person, who is the subject of the medical record, lacks a "societally recognized," constitutionally protected privacy expectation. 90

Second, Miller might be distinguished by arguing that even if it permits the government to obtain medical records from a private source such as a hospital, it does not apply to a tissue sample. Certainly, the analogy between a DNA sample and the records in Miller is, at the very least, debatable, for there may be a more intense privacy expectation in the sample than in the records reflecting the results of a particular test on the sample. The sample represents a greater threat to privacy in that its existence would permit further testing and the revelation of additional information. Although noting that "[t]he precise question as to who owns the blood upon extraction from an individual raises a novel point

without apparent judicial precedent," a New York trial court suggested that the "defendant had a [property] interest in the blood specimen in . . . vial containers" retained by a private hospital. 91 Also, in upholding subpoenas, courts occasionally stress that the records in question were "made [and] kept . . . by the hospital" 92 or that the records were not "personal papers created or kept by the defendant," 93 suggesting that the outcome might be different if the defendant personally had produced the subpoenaed items.

Yet, most courts construe Miller to apply to biological samples as well as to mere records. 94 In Miller, the prosecution sought not only financial statements that the bank had generated, but also checks and deposit slips from the defendant. Miller expressly rejected the argument that there was a significant difference between the documents generated by the bank and those prepared by the depositor. 95 Financial statements prepared by a bank are like medical records prepared by a hospital or laboratory, and checks and deposit slips from the depositor can be analogized to samples from the defendant. To this extent, Miller appears pertinent whether the government seeks the original genetic samples or merely records documenting the results of tests on those samples.

Finally, Miller could be distinguished in that the defendant "voluntarily conveyed" the information to the banks 96 while the voluntariness of providing tissue samples might be questionable. For instance, in People v. Perlos, 97 a leading case 98 involving blood-alcohol testing, a dissenting justice of the Michigan Supreme Court argued that

although under the implied consent statute a driver agrees in advance to a government test of his or her alcohol concentration, the driver does not consent to a search of medical records reflecting a test conducted by a private entity. As the dissent observed, "[i]n today's society, a person has little choice but to undergo medical treatment at a medical facility, generally licensed by and authorized to operate by the state. Few persons have the ability to obtain medical treatment in their homes . . . ." 99 Nevertheless, the majority relied on Miller to uphold a state statute mandating that hospital personnel disclose to the prosecution the results of any blood-alcohol test of a driver involved in an accident. 100

When a conscious person in need of medical treatment is admitted to a hospital, the patient consents to treatment 101 and explicitly or implicitly agrees to medical testing incident to the treatment. The patient therefore voluntarily conveys the data disclosed by the test results to the institution's staff in the same manner that the depositor in Miller "voluntarily conveyed [information] to the banks [to be] exposed to their employees in the ordinary course of business." 102 Given the rules of medical ethics, 103 the patient might have a stronger subjective expectation that the hospital will keep the information in question confidential. However, Miller states that when a person voluntarily reveals information to a third party, for Fourth Amendment purposes the person "takes the risk" that the third party will disclose the information "to Government authorities, even if the information is revealed . . . only

for a limited purpose and the [person expects that] confidence placed in the third party will not be betrayed." 104

In sum, the argument that Miller governs both medical records and samples is strong, but not conclusive. The statutory patterns, restricting the medical privilege and imposing reporting duties on physicians, lend powerful support to the view that there is no reasonable expectation of privacy in medical records or samples. Admittedly, a minority of cases reject this conclusion 105--sometimes on dubious grounds 106--and Miller itself has been the target of intense criticism. 107 However, the majority view is that if the private hospital or laboratory obtains a biological sample on its own initiative for lawful medical reasons, its subsequent surrender of the sample to the authorities does not violate any constitutionally

protected expectation of privacy. 108 The same is true, even more clearly, of laboratory findings or medical records involving the samples. 109 Although it would be desirable to have additional statutory and regulatory protection for medical records, 110 it is difficult to escape the conclusion that under Miller and its progeny, the Fourth Amendment does not confer that protection. 111

However, the Court's recent decision in Ferguson v. City of Charleston 112 complicates the analysis. Ferguson involved a challenge to a set of policies and procedures developed by a public hospital, the Medical University of South Carolina (MUSC), and local law enforcement authorities. 113 MUSC was administering diagnostic tests, including screens for cocaine use, to patients receiving prenatal treatment. If a patient tested positive, the MUSC staff referred her for

counseling and treatment. 114 Despite the referrals, the incidence of cocaine use among the patients remained the same. 115 To give patients a stronger incentive to refrain from drug use, MUSC contacted the local law enforcement authorities. 116 Together, they developed the set of policies and procedures in question. 117 Under these procedures, patients meeting certain criteria were tested for cocaine, and a chain of custody for the sample was maintained. 118 In their final form, the procedures provided that if a woman tested positive for cocaine either during pregnancy or after labor, she would be given an opportunity to avoid arrest by consenting to substance-abuse treatment. 119 The document codifying the policy specified the range of possible criminal charges and the logistics of police notification and arrest. 120

Several women who were arrested challenged the constitutionality of the practice under the Fourth Amendment. 121 A six-justice majority invalidated the program. 122 Six justices agreed that MUSC's surrender of the test results to the police constituted a separate Fourth Amendment intrusion. 123 In response to the public hospital's practice of regularly submitting copies of team documents discussing the women's progress, Justice Stevens wrote that "[t]he reasonable expectation of privacy enjoyed by the typical patient undergoing diagnostic tests in a hospital is that the results of those tests will not be shared with nonmedical personnel without her consent." 124

Although, on its face, this statement is quite broad, Ferguson deals only with a continuing program developed by the police and a public hospital requiring the systematic disclosure of patient records for the "primary purpose" of advancing "the general interest in crime

control." 125 The involvement of law enforcement was so "extensive . . . at every stage of the policy" 126 that the hospital was acting "as an institutional arm of law enforcement." 127

As such, Ferguson is distinguishable from the typical fact situation discussed in Part I.A, namely, a case in which medical personnel in the private sector surrender information that they previously obtained for legitimate, health-related reasons. Indeed, in a footnote, Justice Stevens suggested the distinction between the institutional program in Ferguson and the problem discussed here. 128 After noting the existence of laws requiring medical personnel to report certain types of criminal activity to the police, Justice Stevens stated:

If the medical personnel previously obtained the data from the patient during the course of a regular hospital procedure, they could not be said to have "intentionally set out to obtain incriminating evidence . . . for law enforcement purposes." 130 In that situation, where private medical facilities later surrender information to the authorities, Miller--not Ferguson--presumably would still govern.

The police also might obtain a suspect's DNA sample surreptitiously, without detaining the person. Saliva deposited on a coffee cup at a restaurant, for example, can be collected and analyzed. 131 Police

unsuccessfully chasing a wounded felon might find sufficient blood has dripped onto the sidewalk for DNA profiling to be conducted. It could be argued that such activity is not a search (and hence requires neither probable cause nor a warrant) because the individual, having abandoned the material in a public place, retains no reasonable expectation of privacy in it. The Supreme Court used this reasoning in California v. Greenwood 132 in holding that the Fourth Amendment does not prohibit "the warrantless search and seizure of garbage left for collection outside the curtilage of a home." 133 The Court commented:

However, depositing DNA in the ordinary course of life when drinking, sneezing, or shedding hair, 135 dandruff, 136 or other cells 137 differs from placing private papers in a container on the street to be collected as garbage. Depositing paper in the trash is generally a volitional act. Someone intent on preserving the secrecy of the papers can shred the papers or dispose of them in other ways that would defeat normal police surveillance. Leaving a trail of DNA, however, is not a conscious activity. The deposition of DNA in public places cannot be avoided unless one is a hermit or is fanatical in using extraordinary

containment measures. In this setting, the inference of intent to abandon is markedly weaker.

If the police collection of inadvertently deposited DNA cannot be justified solely on an abandonment theory, under Katz the question becomes whether society does or should recognize as reasonable the expectation that government agents will not follow one about to obtain and analyze DNA that almost inevitably is left in public places. 138 A case can be constructed that such an expectation exists. The public is extremely concerned with preserving genetic privacy. Many states have enacted legislation to preserve the confidentiality of genetic information, and a few have even labeled a person's genotypes as the property of the individual. 139 Furthermore, Skinner v. Railway Labor Executives' Ass'n 140 lends support to this argument. In Skinner, the Federal Railroad Administration had promulgated regulations mandating blood and urine tests of employees involved in certain train accidents and authorizing the railroads to administer breath and urine tests on employees who violated particular safety rules. Some provisions authorized breath and urine tests based on a "reasonable suspicion" of drug or alcohol impairment, but others did not require any showing of individualized suspicion. Railway employees alleged that this system violated their Fourth Amendment rights. The Court of Appeals for the Ninth Circuit invalidated the regulations, holding that the drug testing required reasonable suspicion. 141 The U.S. Supreme Court reversed the court of appeals, reasoning that the compelled collection of breath and urine samples was a search but the practice was reasonable because the government had a special need to ensure that railway personnel were not using substances that might cloud their judgment and impair their performance. 142 The majority recognized

that "[u]nlike the blood-testing procedure at issue in Schmerber, the procedures prescribed by the . . . regulations for collecting and testing urine samples do not entail a surgical intrusion into the body." 143 Nonetheless, the opinion concluded that urine sampling followed by urinalysis was a search, in part because "chemical analysis of urine, like that of blood, can reveal a host of private medical facts about an employee, including whether he or she is epileptic, pregnant, or diabetic." 144 Similarly, DNA testing can reveal "private medical facts" about the individual. 145

However, Skinner is distinguishable in that urinalysis involves a much more extensive intrusion into privacy: the possible revelation of private information, compelled excretion of bodily fluid, and monitoring the normally private act of excretion. 146 Unlike the collection of blood from the suspect in Schmerber, collecting DNA left in public places entails neither a bodily invasion nor a seizure of the person. It seems clear that, in a public restaurant after a suspect departed, the police could pick up a coffee cup used by the suspect and, consistent with the Fourth Amendment, examine it for fingerprints. 147 Courts may find it a small step to conclude that the warrantless collection of inadvertently abandoned DNA does not violate the Fourth Amendment.

Before taking this step, however, courts should consider the extent to which meaningful, personal information that would not be available to private citizens will fall into the hands of government agents interested in accessing this information. When society enters an era in which DNA analyzers are as accessible as home pregnancy-test kits, the argument for an expectation of privacy will be weak. But in a world still at the

threshold of an age of molecular biology, what expectation is reasonable is less obvious. Privacy expectations should turn on the incentives and disincentives for the government to acquire DNA information that is truly sensitive as well as the risk that this information will be used to harm individuals. For law enforcement purposes, there is little incentive to probe areas of the genome that would determine characteristics not discernible to individuals acquainted with a suspect. Identification rarely will be aided by disease prediction, for example, and the risk that police or laboratory personnel will be curious about and well positioned to collect the latter sort of information does not seem large. Rather, there are disincentives to such investigations. The existence of numerous laws restricting the use and release of genetic information on individuals by insurers, employers, and law enforcement personnel is pertinent here. 148 Although further experience with DNA samples in the criminal justice system could lead to a reassessment, for the present the better course is to treat human cells left in public places like fingerprints in deciding what expectation of privacy is reasonable.

In addition to compelling individuals to submit DNA samples or acquiring samples indirectly from medical-care providers, researchers, or from other locations, the authorities might simply ask a suspect to provide a sample. Even if the acquisition of the sample constitutes a seizure under the Fourth Amendment and the authorities do not obtain a warrant or court order, a suspect's consent is an adequate justification for a search or seizure. 149 What, then, must authorities do to obtain legally effective consent? When that question arose with respect to waivers of the privilege against self- incrimination embodied in the Fifth Amendment, early Supreme Court cases applied a general voluntariness test. 150 However, in 1966, the Court mandated in Miranda v. Arizona 151

that the police administer specific warnings to a suspect in custody to ensure that any consent to interrogation was voluntary in the specific sense that the suspect's waiver was intelligent and knowing. 152 In particular, police must advise a suspect of the right to remain silent. 153

The Court has taken a different approach to waivers of one's Fourth Amendment right to be free from unreasonable searches and seizures. In Schneckloth v. Bustamonte, 154 the Court confirmed the continued applicability of a general voluntariness test and expressly held that police need not warn a suspect of the right to refuse to consent to a search. 155 The administration of such a warning is simply one factor in the totality of the circumstances that must be considered in determining the voluntariness of the consent. 156 Schneckloth sharply distinguished between the Fourth and Fifth Amendment settings. The Court emphasiz-ed that while Miranda warnings helped to ensure the reliability of any confession by a suspect, the Fourth Amendment exclusionary rule has little or nothing to do with the reliability of the seized evidence. 157 According to the Court, concerns about the reliability of the evidence and the integrity of the fact- finding process justify a more rigorous standard under the Fifth Amendment than under the Fourth. 158

Although the Schneckloth standard is more lax than the Fifth Amendment test, 159 even Schneckloth has teeth. In some cases, Fourth Amendment consent has been found involuntary. For example, in Bumper v. North Carolina, 160 four police officers went to the house of "a 66-year-old Negro widow . . . located in a rural area at the end of an isolated mile-long dirt road." 161 She met the officers at the front door.

One of them announced, "I have a search warrant to search your house" she responded, "Go ahead," and opened the door. 162 In the kitchen, the officers found the rifle that was later introduced in evidence at the trial of her grandson for rape. The Court reversed the conviction because the officers had no search warrant. 163 The Court explained: "When a law enforcement officer claims authority to search a home under a warrant, he announces in effect that the occupant has no right to resist the search. The situation is instinct with coercion--albeit colorably lawful coercion. Where there is coercion there cannot be consent." 164

Under Bumper, consent to submitting a DNA sample would be involuntary if, for instance, the police gave the suspect the impression that there was no alternative other than to provide the sample. However, on balance, consent should be deemed sufficient when the police make it clear that they seek a sample "for criminal investigation purposes" 165 and avoid statements that could mislead the suspect into believing that there is a legal duty to furnish the sample when there is none. 166

Furthermore, under Scheckloth, the suspect can protect his or her privacy by limiting the scope of the consent. In Florida v. Jimeno, 167 the Supreme Court acknowledged that consent to an intrusion may be limited in scope. 168 For example, a suspect might authorize the warrantless search of an automobile but refuse to consent to a search of the person. 169 By the same token, a suspect could consent to furnishing a DNA sample only for identification purposes in connection with a specific investigation. 170 It would be helpful if police obtained written or

recorded consent for DNA sampling, but there does not appear to be any constitutional requirement to do so. 171

Some European countries have solved difficult murder cases by appealing to all local residents to submit to DNA testing. 172 In perhaps the largest such geographic screening, 16,400 men in western Germany were tested in the hunt for an eleven-year-old girl's killer. 173 A thirty-year-old man arrested after his DNA was found to match confessed to raping, stabbing, and killing the girl, as well as to raping another eleven-year-old girl. 174 In the United Kingdom alone, police have conducted 118 such "mass screens," resulting in forty-eight hits and seven convictions. 175

Geographic screening has been used on a smaller scale in Ann Arbor, 176 Miami, 177 and San Diego. 178 Nothing in the Fourth Amendment prevents the police from approaching everyone in a community and asking for their cooperation. The "dragnet" nature of the inquiry is no obstacle. 179 Consensual contact between a police officer and a citizen is

neither a search nor a seizure under the Fourth Amendment. 180 As a legal matter, police may ask anyone to give DNA and, as long as they do not engage in coercion or misrepresentation, the police may collect voluntary samples for analysis. 181 The practice seems less likely to be effective in this country, however, because the number of residents who could choose not to cooperate might be larger. In addition, the drain on police resources in creating what is, in effect, an ad hoc database would be excessive. 182

To help trace the flow of human populations, geneticists and anthro-pologists have located genetic markers 183 that help distinguish among ancestral populations, and various genes or other DNA sequences are known to have alleles that occur predominantly in certain racial or ethnic groups. 184 In addition, genetic typing permits inferences as to

inherited disorders and may offer clues to facial or other bodily features. 185 Learning that the person whose DNA was found at a crime scene might have such physical characteristics could well be useful in some criminal investigations.

DNA analysis to conduct such "physical profiling" poses few constitutional problems. The principal issue arises under the Equal Protection Clause of the Fourteenth Amendment. Normally, the government is free to draw whatever reasonable lines it wishes in adopting and enforcing the law. The Internal Revenue Service, for instance, can choose to concentrate its investigations of tax evasion on higher-income taxpayers. Some classifications, however, are suspect186 Race is the prototypical example. 187 Imposing the death sentence on the killers of whites but not blacks would be impermissible; 188 likewise, a police officer who adopted a policy of arresting only African-Americans would be depriving those citizens of the equal protection of the law. 189 Does the fact that race is a suspect classification prohibit the government

from conducting or funding research to develop or refine genetic markers for racial identification? Or, when it appears from such markers that the source of the crime-scene DNA is likely to belong to a particular racial or ethnic group, does the Equal Protection Clause prohibit the police from using that fact as an investigative lead and focusing on members of that group?

These questions require an examination of the purpose and impact of the racial classification. That race is a suspect classification does not mean that the government never can inquire into race. 190 To the contrary, the collection and analysis of information about race are commonplace in enforcing the law and in criminological research undertaken or funded by the government. 191 More generally, a great deal of social science and medical research supported or conducted by the government involves the collection of data on race and the analysis of race as a variable of interest. 192 Likewise, if using physical evidence of race to focus an investigation were impermissible, police could not rely on an eyewitness's report that a person fleeing the scene of a crime was Hispanic, on a victim's report that a rapist was white, or on a linguist's analysis of accent or word choice in a recorded death threat that suggested that the caller was African-American. 193 These reports could be in error in any given case, but if they are generally accurate, paying attention to them is not unconstitutional. 194

The government can rely on racial information in a criminal investigation because the practice does not unfairly burden any racial group. 195 In cases in which racial classifications have been struck down, the explicit purpose or actual use of the racial classification was to burden or stigmatize a racial group. Yick Wo v. Hopkins 196 offers an early illustration. In 1880, San Francisco passed an ordinance requiring that persons obtain a permit before operating laundries in wooden structures. Yick Wo was convicted of operating such a laundry without a permit. The Supreme Court set aside the conviction because it concluded that city officials had issued permits with "an evil eye and an unequal hand." 197 Almost without exception, permits were denied to Chinese and granted to non-Chinese. 198 Thus, the permit requirement, although not explicitly racial, was used to exclude the Chinese from the laundry business. It burdened this group for no legitimate reason.

A different question is presented when racial information is collected and used evenhandedly to advance legitimate state interests and in ways that are not designed to disadvantage any individual because of race. In these situations, courts have held the government can record the racial

information. For instance, Hamm v. Virginia State Board of Elections 199 involved an equal protection challenge to a Virginia law that required every decree of divorce to recite the race of the spouses. A three- judge district court upheld this record-keeping provision because the racial information served the valid purpose of collecting social statistics and did not single out or burden any racial group. 200 The Supreme Court affirmed without discussion. 201

Under these principles, governmental sponsorship of research on the variations of particular alleles across races and the investigative use of alleles that are reasonably accurate indicators of race should pass constitutional muster. Two factors are crucial to such constitutionality: No group is singled out for special treatment, and no one is penalized because of hostility toward race. 202 If the police make investigative use

of racial information whenever that information is useful, then all racial groups are treated alike; none is stigmatized or disadvantaged in the enforcement of laws that apply with equal force to members of every race.

It is true that the information could have a disparate impact and lead to the apprehension of more criminals from one race than another--but not because of official (or even unofficial) hostility toward particular races or individual prejudices about those races. Recent years have witnessed outcries against "racial profiling" in policing. 203 The constitutional defect in this practice is that authorities unfairly target minorities for traffic stops or arrests. As in Yick Wo, laws that are neutral on their face--that do not explicitly classify people by race--can be applied disproportionately to racial minorities. 204 With DNA samples from crime scenes, however, statistically valid inferences as to race

cannot lead the authorities to target minorities because of subjective racial stereotypes or prejudices. 205 If anything, by focusing the investigation on the pertinent physical characteristics--whatever they may be--reliance on genetic information in crime-scene samples could correct any tendency to pursue one racial group exclusively or disproportionately. For example, if DNA analysis indicated that the source of a sample was more likely to be Caucasian than African-American, it might help overcome a stereotypical assumption that only blacks need be considered as prime suspects. By providing objective information, DNA analysis could serve as an antidote to the objectionable form of "racial profiling" in police work.

Of course, this is not to say that the government should institute a research program to develop more precise DNA markers for racial identity or that police should use existing markers that are demonstrated to be informative as to race. The conclusion is simply that these are policy choices to be made about a developing technology--these options are not foreclosed by the Constitution.

Two major standards exist for deciding whether scientific findings will be admitted into evidence: the "general-acceptance" test and the "sound- methodology" standard. 206 If a timely objection is raised, the judge must determine whether the applicable standard has been met. The general-acceptance standard was first articulated in an influential 1923 federal court of appeals case, Frye v. United States. 207 In jurisdictions that follow Frye, the proponent of the scientific evidence typically must establish that the underlying theory and methodology are generally accepted within the relevant portions of the scientific community.

The sound-methodology standard is derived from phrases in the Federal Rules of Evidence. In Daubert v. Merrell Dow Pharmaceuticals,

Inc., 208 the U.S. Supreme Court held that these rules implicitly jettison general acceptance as an absolute prerequisite to the admissibility of scientific evidence. 209 Instead of the Frye test, the Court prescribed a broader framework for deciding whether proposed testimony has sufficient scientific validity and reliability to be admitted as relevant "scientific knowledge" that would "assist the trier of fact." 210 In that framework, the lack of general acceptance weighs against admissibility but is not invariably fatal. It is circumstantial evidence that the technology has not been studied widely or that the bulk of the specialists who have studied the technique have found it wanting. The Court discussed other factors that might be considered. Its nonexhaustive list includes the extent to which the theory and technology have been tested, the existence of a body of peer-reviewed studies, and the known error rates of the procedure. 211 Although the trend in the states appears to be toward the Daubert view, 212 there still are jurisdictions that adhere to Frye. 213

Labels like "general acceptance" and "sound methodology" are just that -- labels. Cases decided in each jurisdiction help to define the scientific community in which the degree of scientific acceptance is to be ascertained, the extent of disagreement that can be tolerated, the information that may be used to gauge the extent of consensus, and the specific factors other than general acceptance that bear on relevance and helpfulness. The degree of scientific consensus is important to the admissibility of scientific evidence in all jurisdictions, and pretrial hearings in hotly contested cases have lasted months and generated thousands of pages of testimony probing the opinions of experts on various aspects of DNA profiling. The courts have examined affidavits or testimony from scientists selected by the parties, specific papers in

scientific periodicals, the writings of science journalists, the body of court opinions, and other scientific and legal literature.

In particular, the history of the judicial treatment of DNA evidence can be divided into at least five phases. 214 The first phase was one of rapid and sometimes uncritical acceptance. The first generation of DNA typing tests examined certain Restriction Fragment Length Polymor-phisms (RFLPs) known as Variable Number Tandem Repeats (VNTRs). Bacterial "restriction enzymes" can be used to cut the strands of the DNA molecule when they encounter certain, short sequences of bases ("restriction sites"). 215 The resulting fragments vary in their lengths; some have more base pairs between two adjacent restriction sites. One class of such length polymorphisms is due to repetitions of "core sequences" some fifteen to thirty-five base pairs long. 216 These core sequences are repeated end-to-end different numbers of times in different individuals. Because of the many repeats, these VNTR alleles typically extend for thousands of bases. 217 Between each pair of restriction sites, an individual usually has two fragments of distinct lengths (one from each chromosome). The two lengths can be measured by electrophoresis, a process that sorts fragments by length. 218

Initial praise for RFLP testing in homicide, rape, paternity, and other cases was effusive. Indeed, one judge proclaimed "DNA fingerprinting" to be "the single greatest advance in the 'search for truth' . . . since the advent of cross-examination." 219 In this first wave of cases, expert testimony for the prosecution rarely was countered, and courts readily admitted RFLP findings. 220

In a second wave of cases, however, defendants pointed to problems at two levels--controlling the experimental conditions of the analysis and interpreting the results. 221 Some scientists questioned certain features of the procedures for extracting and analyzing DNA employed in forensic laboratories. It became apparent that determining whether RFLPs in VNTR loci in two samples actually match can be complicated by measurement variability 222 or missing or spurious bands. 223 Despite these concerns, most cases continued to find forensic RFLP analyses to be generally accepted, 224 and a number of states have provided for admissibility of DNA tests by legislation. 225 Concerted attacks by

defense experts of impeccable credentials, however, produced a few cases rejecting specific proffers on the ground that the testing procedure was not sufficiently rigorous. 226 Moreover, a minority of courts, perhaps concerned that DNA evidence might well be conclusive in the minds of jurors, added a "third prong" to the general acceptance standard. 227 This augmented Frye test requires not only proof of the general acceptance of the ability of science to produce the type of results offered in court, but also a showing of the proper application of an approved method on the particular occasion. 228 Whether this inquiry is properly part of the special screening of scientific methodology, however, is debatable. 229

A different attack on DNA profiling that began in cases during this period proved far more successful and led to a third wave of cases. Even if the laboratory has found the true VNTR profile in the sample and has correctly determined that it matches the defendant's,there is some chance that the match is a coincidence because the perpetrator actually was someone else whose VNTR profile happens to be the same as the defendant's. To dismiss this possibility as remote, prosecutors called on experts to testify that the probability of a coincidentally matching VNTR profile (often called a "random- match probability") is infinitesimal. However, these estimates relied on a simplified population-genetics model for the frequencies of VNTR profiles that treats each race as a large, randomly mating population. Some prominent scientists claimed that the applicability of the model had not been adequately verified. 230 They suggested that within a broad population group such as Caucasians, subgroups such as Italian-Americans and Swedish-Americans tend to mate among themselves and might have very different frequencies for the VNTR alleles. Such a population structure could cause the simplified estimates to understate (or overstate) the profile frequency for Caucasians derived from data that fail to account for the effects of the subpopulations. A heated debate spilled over from courthouses to scientific journals and convinced the supreme courts of several states that general acceptance was lacking. 231 A 1992 report of the National Academy of Sciences proposed a more "conservative" computational method as a compromise, 232 and this seemed to undermine the claim of scientific acceptance of the less conservative procedure that was in general use. 233

At this juncture, the debate was poised to enter a fourth phase. In response to the population-genetics criticism and the 1992 NAS report 234

came an outpouring of both critiques of the report and new studies of the distribution of VNTR alleles in many population groups. Relying on the burgeoning literature, a second National Academy panel concluded in 1996 that the usual method of estimating frequencies of VNTR profiles in broad racial groups was sound. 235 In the fourth phase of judicial scrutiny of DNA evidence, the courts almost invariably returned to the earlier view that the probabilities estimated with the random-mating model (or minor variations of it) are generally accepted and scientifically valid. 236

The fifth phase of the judicial evaluation of DNA evidence is well underway. Harnessing the Polymerase Chain Reaction (PCR) enables laboratories to produce millions of identical copies of DNA fragments even from samples too small for RFLP typing. 237 With these in hand, many DNA polymorphisms can be analyzed quickly and unambiguously. 238 Consequently, the RFLP methods "are being rapidly replaced" with PCR-based methods. 239 As results obtained with new methods enter the courtroom, it becomes necessary to ask whether each such method rests on a solid scientific foundation or is generally accepted in the scientific community. 240 Sometimes, the answer will be obvious even

without an extensive pretrial hearing. 241 The opinions are practically unanimous in holding that the more commonly used PCR-based procedures satisfy these standards. 242

In sum, in little more than a decade, DNA typing has made the transition from a novel set of methods for identification to a relatively mature and well studied forensic technology. However, one should not lump all forms of DNA identification together. New techniques and applications continue to emerge. These range from the use of new genetic systems and new analytical procedures to the typing of DNA from plants and animals. 243 Before admitting such evidence, it will be necessary to inquire into the biological principles and knowledge that would justify inferences from these new technologies or applications. 244 For example, a court's prior approval of RFLP testing by gel electrophoresis 245 or reverse dot blot testing 246 of PCR-amplified fragments

containing the HLA DQ-a1 gene 247 does not dictate the conclusion that the court also must accept testing at STR loci 248 or mitochondrial DNA sequencing. 249 The newer technologies are gaining judicial approval, 250 but a court should not confer approval until it is satisfied that the specific technology satisfies the applicable standard.

In a study, the researchers empirically verify the ability of the technology to identify features of DNA molecules. In contrast a proficiency study tests how competently the laboratory's analysts apply a technology that has been validated. 251 The purpose of proficiency testing is to uncover difficulties that a particular technician or a particular laboratory might be encountering in applying established methods.

Proficiency testing raises a variety of legal issues. It has been suggested that participation in a program of proficiency testing ought to be a prerequisite to the admission of evidence from a forensic laboratory, 252 that proficiency-test results should be admissible to show how likely it is that the laboratory erred in the test at bar, 253 and that random-match probabilities ought to be inadmissible unless they are combined with proficiency-test results to estimate the probability of a false match. If the second suggestion is followed, and the defense is allowed to introduce evidence of proficiency tests to suggest that the laboratory is prone to err, a further question arises: Should the prose-cution be permitted to present testimony that the defense has not retested or even requested the opportunity to retest the samples? 254

The first suggestion, that courts condition admissibility on proficiency testing, is a departure from the usual practice. As indicated in the previous section, the scientific-validity and general-acceptance standards relate to the capacity of an analytical procedure to generate accurate results when properly applied, and not to whether the individual or institution using a valid or generally accepted method is skilled and careful or is instead careless and prone to error. 255 Of course, the latter issue can be of paramount importance, but usually it is said to be a matter affecting the weight of the evidence rather than its admissibility. 256

The second suggestion, that testimony about proficiency-test results be used to reveal the chance of error in the case at bar, presupposes that such evidence is admissible at trial. 257 In its 1992 report, a committee of the National Academy of Sciences took the position that "laboratory error rates must be continually estimated in blind proficiency testing and must be disclosed to juries." 258 There is authority that when the prose-cution introduces testimony about the probability of a coincidentally matching profile, the defendant is entitled to introduce testimony about the laboratory's proficiency tests. 259 Indeed, it has been held that the opponent must be allowed to cross-examine one laboratory representative about errors committed by other analysts at the laboratory. 260

In contrast, in a report published in 1996, a second committee of the National Academy of Sciences declined to take a position on whether evidence of laboratory error rates, as estimated from proficiency studies, should be admissible at trial. 261 However, the report's discussion of proficiency testing raises questions about the probative value of such evidence. For example, the report notes that "[t]he pooling of proficiency-test results across laboratories" could mislead a jury and "penalize the better laboratories." 262 It adds that even a test of the same laboratory might be outdated, because the laboratory may have taken

corrective action. 263 In these circumstances, the testimony could be vulnerable to an objection under Federal Rule of Evidence 403, which requires the exclusion of evidence whose probative value is substantially outweighed by the danger of prejudice, confusion of the issues, or undue consumption of time. 264

A further objection is that the testimony represents inadmissible character evidence. 265 If the theory of logical relevance is merely that the laboratory's past commission of errors increases the probability that the laboratory erred on the occasion in question, then the theory amounts to forbidden character reasoning. 266 This is precisely the theory of logical relevance generally banned by Federal Rule of Evidence 404. 267 Moreover, to the extent that proficiency-test results constitute evidence of specific acts introduced to show a general tendency to make mistakes, they seem to run afoul of Rule 405, which forbids this form of character

evidence. 268 One might argue that the character rules do not apply to entities such as a laboratory. However, the language of the rules is broad enough to extend to businesses and other entities; 269 and the cases have generally construed the statutes as reaching entities as well as natural persons. 270

This issue is rarely recognized as a character-evidence problem in the trial court, 271 but a trial judge might find it difficult to justify overruling a properly phrased character-evidence objection when the theory of relevance is nothing more than a general tendency of the laboratory to make mistakes. If there is a consensus that the jury sometimes needs the proficiency-test results as an antidote to overwhelmingly small random-match probabilities, then the federal and state rules governing character evidence should be altered to give the trial court the discretion to admit the evidence. 272

Moreover, both the bench and bar should appreciate that in some circumstances proficiency tests of the laboratory involved in the case should be held admissible without relaxing the ban on character evidence. The ban applies only when the sole theory of logical relevance is that the existence of errors in the past suggests a tendency to err that might affect the result in the case at bar. There might be situations in which the defense can use the test data at trial on an entirely different theory of logical relevance. Assume, for instance, that the experts in a case disagree over whether a peak or a band observed in a DNA test is due to an allele or is an artifact. 273 Evidence that spurious peaks or bands have occurred under similar circumstances in proficiency tests of the laboratory on known samples would lend support to the defense theory that the peak or band in the pending case is an artifact. 274 In this situation, proficiency-test data are relevant because they provide information about the operating characteristics of the DNA test at that particular laboratory. 275

The third argument relating to proficiency testing is that estimates of the probability that a randomly selected person would have the DNA type found in a crime-scene sample should be inadmissible unless accompanied by or blended with the laboratory's error rate. 276 The 1996 committee observed that combining the probability of a random match with the probability of error "would deprive the trier of fact of the opportunity to evaluate separately the possibility that the profiles match by coincidence as opposed to the possibility that they are reported to match by reason of laboratory or handling error." 277 The committee took the position that "a calculation that combines error rates with match

probabilities is inappropriate." 278 The reasoning supporting the committee's position essentially sounds under Federal Rule of Evidence 403. 279 If anything, the Rule 403 objection is more substantial here than when it is urged as a basis for excluding testimony offered to impeach the laboratory's competence. In this situation, the questions about the validity of industry-wide error rates and the staleness of even the laboratory's own tests are equally applicable and call into question the probative worth of the testimony. Moreover, there is a heightened risk that the jury will be confused. Error rates and random-match probabil-ities relate to distinct hypotheses, and a lay juror may find it difficult to understand the significance of a computation which merges the rates and the probability. That mode of computation could place even greater strain on the jurors' ability to comprehend the body of evidence submitted to them. 280 The few courts that have addressed the argument that error rates should be used to the exclusion of random-match probabilities have not been persuaded. 281

While defense counsel originated the first three suggestions, the fourth suggestion related to proficiency testing has been made by prosecutors. The thrust of this suggestion is that when the defense is allowed to introduce evidence of proficiency tests of the laboratory employing the prosecution's expert to suggest that the laboratory is prone to err, the prosecution should be permitted to present testimony that the defense has not retested or even requested the opportunity to retest the samples analyzed by the prosecution's expert.

The testimony would be logically relevant under several theories. First, if a defense expert testifies that the laboratory result is untrustworthy,

the failure to retest would be relevant to impeach the defense expert's credibility on the ground that a scientist who truly doubted the accuracy of the analysis normally would have retested the samples to resolve the matter. 282 Inasmuch as replication is a crucial and common feature of scientific inquiry, 283 it could be argued that neglecting to retest is prior inconsistent conduct. On this theory, the defense would be entitled to a limiting instruction to the effect that the expert's failure to retest is not offered to show that the test result is correct, but only to demonstrate that the defense expert is not sincere in asserting that it is flawed. 284

The probative value of a failure to retest in showing an expert's insincerity, however, is open to question. It is not uncommon for scientists to question in print or otherwise the adequacy of another researcher's experiment before undertaking to replicate it. And even if such opinions were unheard of in the course of ordinary science, the expert may have been retained for the limited purpose of giving an opinion on the adequacy of the testing that was done rather than redoing that testing. Nevertheless, the inference of insincerity need not be particularly strong for the "inconsistent" conduct to be a proper, logically relevant subject for cross-examination. 285

Second, if the defense expert offers an opinion that the laboratory's results may be in error, the expert's failure to request or conduct an independent test would be relevant to suggest that the jury should give less weight to that opinion. 286 The prosecution could argue to the jury that an expert who fails to use a more definitive and readily available procedure for ascertaining whether the initial test results are correct has not been thorough in evaluating those results, and that such experts

deserve little credence because the basis for the opinion is not as complete as it could be. Again, the inference may be debatable, but the standard of relevance, particularly on cross-examination, is lenient. 287

Third, whether or not a defense expert discusses proficiency tests, the prosecution could argue that the defense's failure to retest (or to request a retest) amounts to an admission of the accuracy of the initial test by conduct by the defendant. 288 The courts have applied the admission-by- conduct theory to a litigant's failure to present evidence when "it would be natural" for the litigant to introduce such testimony. 289 The prosecution might urge that it would be natural for a defendant affected by a false match to seek retesting and that it would be natural for a DNA expert who entertained serious doubts about the accuracy of a prior test to retest the samples. 290

In short, there are reasonable arguments for permitting the prose-cution to raise the issue of retesting when a defendant questions the laboratory's ability to type DNA samples correctly. But even if the inquiry is probative of the insincerity or lack of thoroughness of the expert, or an admission by the defendant, there are potential objections to this counterthrust by the prosecution. One objection is that the inquiry is inconsistent with the prosecution's burden of proof. 291 To reinforce the allocation of the burden to the government, some courts generally forbid prosecution comment on the defense failure to produce evidence. 292 The argument runs that the defense is entitled to rely on the burden and has no obligation to present any evidence at trial. According to this line of argument, it is improper to convert the defense's failure to present testimony into prosecution evidence. 293 Under this line of authority, the

defense could bar prosecution comment about the defense's failure to retest the DNA sample. However, even in such a jurisdiction, if the defense overreached, prosecution comment might be permitted as an invited response. 294 In addition, some jurisdictions reject that line of authority and allow comment on the defense's failure to present exculpatory evidence, 295 so long as the trial judge clearly instructs the jury that the prosecution has the ultimate burden of proof.

A further objection is that the admission of the testimony is inconsistent with the defendant's attorney-client privilege. A number of jurisdictions apply the attorney-client privilege when, as part of trial preparation, defense counsel hires an expert to evaluate private infor-mation from the defendant, such as the defendant's mental or physical condition. 296 The Advisory Committee Note to draft Federal Rule of Evidence 503 endorsed the application of the attorney-client privilege to experts' 297 and some courts have gone to the length of invoking the theory even when the expert did not evaluate information realistically originating from the defendant. 298 Based on these authorities, the defense might contend that the attorney-client privilege applies to a defense expert's retest of a DNA sample. The gist of the objection would be that if the result of a retest would be privileged, it is wrong-minded to penalize the defense for failing to retest.

As with the other suggestions related to proficiency testing, the case law offers little guidance. In principle, it would seem that once the defense has sharpened the issue of the prosecution expert's use of proper test procedures, the prosecution should be allowed to elicit testimony about the defense's failure to retest at least to probe the basis for the expert's opinion and as circumstantial evidence of defendant's belief that retesting would not yield a different result. The fact that the prosecution has the burden of persuasion does not make such inferences impermissible. 299 The constitutional requirement for proof beyond a reasonable doubt regulates the quantum of proof the prosecution must present, but no court has invoked the requirement to preclude the prosecution from introducing an otherwise admissible item of evidence. In appropriate circumstances, the majority of courts permit prosecutors to comment on a defendant's failure to produce evidence such as an available witness who would presumably corroborate the defendant's testimony. 300

Neither should the attorney-client privilege pose an insurmountable barrier. Certainly, the prosecution cannot comment on a defendant's decision to exercise a constitutional privilege, 301 and comment on a defendant's failure to produce a witness is often forbidden when the defendant stands in a privileged relationship with the witness. 302 Consequently, it might be justifiable to apply the attorney-client privilege to a defense expert's actual analysis of material that has become available because of the defendant's exercise of the right to prepare a defense with the assistance of counsel. Perhaps material that both emanates from the defendant and is still confidential would fall into this category. However, these conditions do not seem to be satisfied in

this setting. The DNA sample that the defendant suggests has been improperly analyzed might be crime-scene material that was not obtained from the defendant, or it could be a sample that the prosecution lawfully acquired from the defendant. In these situations, the attorney-client privilege should not preclude adverse comment on the defense's failure to retest.

The power of DNA evidence has prompted proposals to create an exception to the statute of limitations for sexual assault when DNA profiling links the suspect to the assault. 303 Moreover, some prosecutors have attempted to avoid the tolling of the statute by filing "John Doe" arrest warrants based solely on a description of the unnamed assailant's DNA. 304 However, devising a workable "DNA exception" that would respect the interests of defendants and society in defining a point after

Statutes of limitations serve a variety of purposes. Most obviously, they protect individuals against the risk that they will unable to assemble adequate evidence for a defense because too much time has passed since the alleged crime was committed. With time, memories fade, evidence is misplaced, witnesses become harder to locate, and the accused's ability to defend himself is reduced. 306 Thus, the Supreme Court has described statutes of limitations as "the primary guarantee against bringing overly stale criminal charges." 307 In addition, they give innocent (as well as guilty individuals) a certain peace of mind and encourage the police to move on to more recent cases that are more likely to be solved and for which punishment would be more effective. 308

A DNA exception attends only to the first justification for statutes of limitations. If a comparison of the defendant's DNA with the trace evidence DNA collected many years ago were to establish conclusively that the defendant is guilty, 309 then it could be argued that any degradation in the defendant's ability to mount a defense would be harmless because it could not affect the outcome of the trial. For example, even when a defendant's alibi witness had died after the

statutory period, if no reasonable jury could have believed the alibi in the face of the DNA proof, the availability of the witness could not have resulted in an acquittal.

The premise that DNA evidence is dispositive, however, is not always true. First, there are cases in which a defendant might succeed in raising a reasonable doubt about the reported results of the DNA tests. This situation would arise, for instance, when there is reason to think that samples were switched or cross-contaminated in the laboratory or in the collecting and handling of the trace evidence before it reached the laboratory. Many years later, the police officers and laboratory personnel involved could be impossible to locate, and the written records remaining might be inadequate to resolve these claims.

Second, even if one were to conclude that such cases are too rare to be an obstacle to creating an exception to the statute, DNA evidence can be conclusive only as to one factual issue--whether the DNA in the trace evidence somehow originated from the defendant. Without more, proof of that factual issue ordinarily falls far short of demonstrating guilt for every type of sexual assault. Thus, a defendant's semen might be present on an alleged victim's clothing or a bedsheet even if there had been no penetration, and it would be expected to be found in a vaginal swab if the sex had been consensual. 310

The legislature might try to respond to these concerns by confining the DNA exception to cases in which identity is the only issue that needs to be resolved. 311 But which cases are these? Can a defendant avoid the extension of the period of limitations by conceding his identity as the source of the trace evidence but alleging that he reasonably believed that the woman invited his actions, that he was acting under duress, or the like? Should the court be required to find that these defenses have no basis in fact for the prosecution to proceed after the statute has run? It might be possible to draft a suitably sensitive DNA exception to the

statute of limitations, but the task is not so simple as, initially, it might appear to be.

In contrast, the situation is much simpler when a defendant brings forward DNA evidence in a case involving a single rapist that shows that the DNA in the trace evidence is not his. If that evidence is believed, then he is not the guilty party. But while DNA evidence can be conclusive of innocence, DNA evidence is not logically sufficient to prove guilt. Because identity is not the only element of the offense and because there are affirmative defenses that can be pled, even when the state brings forward incontestable DNA evidence of identity, the defendant might not be guilty of sexual assault. Consequently, it would be consistent to advocate an extension of the period in which post- conviction relief can be sought 312 while opposing an extension of the statute of limitations.

This Article has canvassed a wide variety of issues. Some are constitutional in nature, others are statutory, and still others arise at common law. The character of the issues ranges from substantive criminal law to procedure to evidence. While the issues are diverse, they share two related common denominators. One is their relative novelty, and the other is the consequent paucity of case law analyzing the issues. In the past decade, a dizzying array of DNA technologies--from gel electrophoreses of single-locus RFLPs, to PCR- based studies of STRs, to mitochondrial DNA sequencing--has materialized in American court-rooms. The predictable result has been a proliferation of evidentiary issues. Yet, several important questions have received little in the way of careful consideration. This Article has identified and ventured answers to these questions. As stated at the outset, despite their novelty, some of these issues admit of relatively clear answers. In other cases, though, their resolution will demand a sophisticated balancing of competing public policy considerations. If the criminal justice system is to realize the full potential of DNA technology while maintaining its essential fairness, the system must come to grips with these issues in short order.

* Professor, University of California at Davis School of Law; J.D., B.A., University of San Francisco.

** Regents' Professor, Arizona State University College of Law; Fellow, Center for the Study of Law, Science, and Technology; J.D., Yale Law School; M.A., Harvard University; B.S., Massachusetts Institute of Technology.

1. The earliest instance of DNA analysis for legal purposes is reported in Alec J. Jeffreys et al., Positive Identification of an Immigration Test-Case Using Human DNA Fingerprints, 317 Nature 818 (1985) (applying the multilocus probes described in Alec J. Jeffreys et al., Individual-Specific "Fingerprints" of Human DNA, 316 Nature 76 (1985), and Alec J. Jeffreys et al., Hypervariable "Minisatellite" Regions in Human DNA, 314 Nature 67 (1985)). Soon after, this group applied the technique to a serial-murder case described at length in Joseph Wambaugh, The Blooding 71-75, 79-82, 146-47, 150-54, 156-57, 167-71, 213-18, 227-28, 275, 282, 284 (1989), excluding one suspect and incriminating another. In the United States, another form of DNA typing made its debut in an unreported Pennsylvania case, Commonwealth v. Petinikis. See Committee on DNA Technology in Forensic Science: An Update, National Research Council, The Evaluation of Forensic DNA Evidence 174 n.18 (1996) [hereinafter NRC II].

2. See, e.g., Gina Kolata, Some Scientists Doubt the Value of "Genetic Fingerprint" Evidence, N.Y. Times, Jan. 29, 1990, at A1 ("Leading molecular biologists say a technique promoted by the nation's top law enforcement agency for identifying suspects in criminal trials through the analysis of genetic material is too unreliable to be used in court."). Several of the biologists referred to in this story complained that their views were misrepresented, but the New York Times declined to print their letters to the editor. See Andre A. Moenssens, DNA Evidence and Its Critics--How Valid Are the Challenges?, 31 Jurimetrics J. 87, 99-100 (1990).

3. See, e.g., Marjorie M. Shultz, Reasons for Doubt: Legal Issues in the Use of DNA Identification Evidence, in DNA on Trial: Genetic Identification and Criminal Justice 19 (Paul R. Billings ed., 1992), reviewed by John F.Y. Brookfield, Gene Justice, 363 Nature 122 (1993) (dismissing the criticism as "parochial nonsense").

4. See, e.g., Janet C. Hoeffel, Note, The Dark Side of DNA Profiling: Unreliable Scientific Evidence Meets the Criminal Defendant, 42 Stan. L. Rev. 465 (1990).

5. For reviews of the challenges to admissibility, see Paul C. Giannelli, The DNA Story: An Alternative View, 88 J. Crim. L. & Criminology 380 (1997) (concluding that courts were too willing to admit an untested technology); David H. Kaye, DNA Evidence: Probability, Population Genetics, and the Courts, 7 Harv. J.L. & Tech. 101 (1993) (suggesting that the principal objection to the computations of random-match probabilities was exaggerated); William C. Thompson, Evaluating the Admissibility of New Genetic Identification Tests: Lessons from the "DNA War," 84 J. Crim. L. & Criminology 22 (1993) (reviewing the debate on population structure but not discussing studies indicating that the effect is generally minor). Some of the leading court opinions are reproduced in D.H. Kaye, Science in Evidence 167-206 (1997).

7. This Article builds on a report prepared by the authors for the Legal Issues Working Group of the National Commission on the Future of DNA Evidence, entitled Forensic DNA Typing: Selected Legal Issues (2000). The authors are grateful to Paul Bender, Susan Ehrlich, Rockne Harmon, Dorothy Nelkin, Barry Scheck, Michael Smith, Ralph Spritzer, Jeffrey Thoma, William Thompson, James Weinstein, and Richard Willing for information, comments, discussions, or arguments about topics discussed in this Article.

8. This Article does not consider legal issues associated with collecting or using DNA from individuals who are not specifically suspected of the crime that is under investigation. These issues are central to building and administering many DNA databases for law enforcement and will be addressed in a separate article that is in progress. The most comprehensive treatment published to date is Michelle Hibbert, DNA Databanks: Law Enforcement's Greatest Surveillance Tool?, 34 Wake Forest L. Rev. 767 (1999). For rejoinders to some of the criticisms advanced there, see D.H. Kaye, Bioethics, Bench, and Bar: Selected Arguments in Landry v. Attorney General, 40 Jurimetrics J. 193 (2000); David H. Kaye & Edward J. Imwinkelried, Forensic DNA Typing: Selected Legal Issues (2000). For discussion of the acquisition of DNA for the purpose of proving that a convict is innocent, see Cynthia Bryant, When One Man's DNA Is Another Man's Exonerating Evidence: Compelling Consensual Sexual Partners of Rape Victims to Provide DNA Samples to Postconviction Petitioners, 33 Colum. J.L. & Soc. Probs. 113 (2000).

9. It does so by suggesting that the suspect is the source of the crime-scene DNA. Of course, other explanations may exist. The match might be a laboratory artifact, it might be coincidental in that an unrelated person is the source of the trace evidence, or the match could be the result of kinship in that a close relative of the defendant is the source. Suitable investigative and testing procedures often can eliminate such alternative hypotheses. See David H. Kaye & George F. Sensabaugh, Jr., Reference Guide on DNA Evidence, in Reference Manual on Scientific Evidence 485 (Federal Judicial Center ed., 2d ed. 2000).

10. As with an inclusion, there can be other explanations for a reported exclusion. See Kaye & Sensabaugh, Jr., supra note 9.

11. The Self Incrimination Clause of the Fifth Amendment and the Due Process Clauses of the Fifth and Fourteenth Amendments have less force in this context. See D.H. Kaye, The Constitutionality of DNA Sampling on Arrest, 10 Cornell J.L. & Pub. Pol'y (forthcoming 2001); cf., e.g., Schmerber v. California, 384 U.S. 757, 760-65 (1966) (rejecting such claims with regard to involuntary taking blood from an individual suspected of driving while intoxicated for the purpose of measuring his blood alcohol concentration shortly after he had been injured in an automobile accident).

12. Some state constitutions provide enhanced protection from searches and seizures and other police practices. For example, in United States v. Robinson, 414 U.S. 218 (1973), and Gustafson v. Florida, 414 U.S. 260 (1973), the Court authorized broad searches incidental to the lawful arrest of a person. Robinson, 414 U.S. at 230-35; Gustafson, 414 U.S. at 263-66. Under their state constitutions, several courts have refused to follow Robinson and Gustafson. See, e.g., State v. Taylor, 808 P.2d 324 (Ariz. 1990); People v. Innis, 604 N.E.2d 389 (Ill. Ct. App. 1992); State v. Hoskinson, 879 P.2d 180 (Or. 1994).

21. See, e.g., People v. Marshall, 244 N.W.2d 451, 457 (Mich. Ct. App. 1976); In re J.W.K., 583 N.W.2d 752, 755 (Minn. 1998); State v. Evans, 338 N.W.2d 788, 794 (Neb. 1983); In re Death of Abe A., 437 N.E.2d 265, 266 (N.Y. 1982); Commonwealth v. Riedel, 651 A.2d 135, 139 (Pa. 1994).

23. See Bickley v. State, 489 S.E.2d 167, 170 (Ga. Ct. App. 1997) (rejecting the claim that investigators violated Fourth Amendment by using a DNA sample taken pursuant to a search warrant in a 1994 rape investigation to convict a man of two earlier rapes as well as the 1994 rape); Smith v. State, 734 N.E.2d 706, 709-10 (Ind. Ct. App. 2000) (involving DNA obtained by court order in rape case in which defendant was acquitted on a consent defense; police found a match between this DNA sample and a profile in the state's database of DNA from unsolved crimes; the court held the database check was constitutional because "police conduct in comparing Smith's court-ordered DNA sample with the DNA obtained from the V.O. rape is not a Fourth Amendment search or seizure"); Wilson v. State, 752 A.2d 1250, 1268-72 (Md. Ct. Spec. App. 2000) (stating that because "[n]o new Fourth Amendment intrusion is involved," use of a previously legally obtained sample to link defendant to present crime obviated need for new warrant even though police had obtained one); People v. King, 663 N.Y.S.2d 610, 614 (App. Div. 1997) (stating that police could use the profile from a sample obtained under a warrant with probable cause in a second rape investigation even if they lacked probable cause to acquire the sample for that investigation because "once a person's blood sample has been obtained lawfully, he can no longer assert either privacy claims or unreasonable search and seizure arguments with respect to the use of that sample").

24. Because the invasion of privacy was justified (by probable cause and a warrant for seizing the DNA and searching its structure), the conventional additional-use theory would allow the later further comparisons. See supra note 23. An analogy can be drawn to the situation in which police searching a dwelling for specific stolen items record the serial number of an item not enumerated in the warrant and check this number against a list of serial numbers of other stolen items. Recording the serial number would not be considered a search if the number was in plain view. Cf. Arizona v. Hicks, 480 U.S. 321, 324-25 (1987) ("[T]he mere recording of the serial numbers did not constitute a seizure, [but] taking action, unrelated to the objectives of the authorized intrusion, which exposed to view concealed portions of the apartment or its contents, did produce a new invasion of respondent's privacy unjustified by the exigent circumstance that validated the entry."). Under the additional-use theory, checking the number against a list is not an additional search of the person or the property and therefore would be allowed. Cf. State v. Wamre, 599 N.W.2d 268, 274-77 (N.D. 1999) (holding that the Fourth Amendment was satisfied when the police used a serial number that was in plain view during a search to secure a warrant by telephone that allowed them to seize the additional items).

The logic of the existing Fourth Amendment doctrine has been sharply questioned. See Harold J. Krent, Of Diaries and Data Banks: Use Restrictions Under the Fourth Amendment, 74 Tex. L. Rev. 49, 53 n.25 (1995) (arguing that the current understanding of the Fourth Amendment should be altered so that "each governmental use of information about an individual constitutes a separate seizure of that person's effects" and hence "all such uses must satisfy the reasonableness requirement").

25. A valid arrest requires probable cause to believe that the individual has committed an offense. Alternatively, the presence of exigent circumstances may justify a seizure in the absence of a warrant. This was the basis for upholding the search in Schmerber v. California, 384 U.S. 757 (1966). The Court reasoned that there was an exigency because blood-alcohol concentrations decline rapidly. Id. at 770-72. However, DNA cases are readily distinguishable. In the typical case, the police desire a DNA sample to test for permanent, identifying markers--markers that will not evaporate or disappear with the mere passage of time. Consequently, it will be more difficult for the authorities to justify a warrantless seizure of a DNA sample than it would be to justify a similar acquisition of a blood sample for intoxication testing. See In re J.W.K., 583 N.W.2d 752, 757 (Minn. 1998). In the absence of exigent circumstances, the police would be obliged to obtain the functional equivalent of a warrant, that is, a court order that the suspect furnish a DNA sample. See Thurman v. State, 861 S.W.2d 96, 100 (Tex. Ct. App. 1993).

26. See Kaye, supra note 11 (describing the types of sampling and the protections on disclosure of the information that might be required to satisfy the Due Process and the Search and Seizure Clauses of the Bill of Rights). Of course, a state may adopt a more restrictive approach under its own constitution. See generally Darien A. McWhirter & John D. Bible, Privacy as a Constitutional Right 174, 178 (1992); Richard C. Turkington & Anita L. Allen, Privacy Law 122-25 (1999) (listing state constitutional provisions).

27. See supra note 23. Under City of Indianapolis v. Edmond, 121 S. Ct. 447 (2000), and Ferguson v. City of Charleston, 121 S. Ct. 1281 (2001), the reuse would not be allowed if the samples from arrestees were obtained as part of a program that had as its primary goal the acquisition of DNA samples for later database searches. See Kaye, supra note 11.In addition this reuse would not be acceptable under the theory advanced in Krent, supra note 24, at 53 n.25. A narrower version of this view holds that when the police rely on a special justification to deviate from the normal Fourth Amendment requirements of probable cause or a warrant, their utilization of the evidence seized must be limited to uses that promote that special justification. Thus, if as in Schmerber v. California, 384 U.S. 757 (1966), the police justify a warrantless seizure of evidence on the theory that blood alcohol testing requires a sample to be taken without further delay, they could not use the blood sample for DNA testing. This narrower version has merit, although no published opinion has embraced it as a basis for excluding evidence.

37. For discussions of the statutes and court rules adopted by the various states, as well as the court rule proposed for federal practice, see Jerold H. Israel, Legislative Regulation of Searches and Seizures: The Michigan Proposals, 73 Mich. L. Rev. 222, 238-41 (1974); Angus J. Dodson, Comment, DNA "Line-Ups" Based on a Reasonable Suspicion Standard, 71 U. Colo. L. Rev. 221, 234-38 (2000); Note, Detention to Obtain Physical Evidence Without Probable Cause: Proposed Rule 41.1 of the Federal Rules of Criminal Procedure, 72 Colum. L. Rev. 712 (1972).

39. The Arizona statute specifies that "'identifying physical characteristics' includes, but is not limited to, the fingerprints, palm prints, footprints, measurements, handwriting, handprinting, sound of voice, blood samples, urine samples, saliva samples, hair samples, comparative personal appearance or photographs of an individual." Id. �13-3905(G).

40. Clyde M. Tande, Note, DNA Typing: A New Investigatory Tool, 1989 Duke L.J. 474 (describing the breadth of the language of the various state statutes and court rules). For example, Alaska Rule of Criminal Procedure 16(c) allows a court to order detention to "[p]ermit the taking of samples of blood, hair and other materials of the person's body which involve no unreasonable intrusion thereof" on the basis of an affidavit or testimony establishing probable cause to believe that: (i) An offense has been committed by one of several persons comprising a narrow focal group that includes the subject person; (ii) The evidence sought may be of material aid in identifying who committed the offense; and (iii) The evidence sought cannot practicably be obtained from other sources. Alaska R. Crim. P. 16(c)(2)(vii) & 16(c)(1).

Although the Supreme Court has not ruled authoritatively on the constitutionality of these procedures, in Hayes v. Florida, 470 U.S. 811 (1985), the Court referred approvingly to its previous statement in Davis. Id. at 817.

42. Id. at 617. Read in context, however, this language does not necessarily support imposing a requirement of probable cause. In Skinner, the Supreme Court was reviewing a judgment of the Ninth Circuit Court of Appeals striking down the drug testing regulations because they did not require any showing of individualized suspicion--not even reasonable suspicion, let alone probable cause. Id. at 612-13. The majority merely mentioned "private medical facts" in estab-lishing that urinalysis constitutes a search. Id. at 617. It does not follow from the fact that a search is involved that probable cause is required. That is precisely the point made in Davis, where the Court indicated its willingness to relax the probable cause requirement for the undeniable searches or seizures involved in compelling a suspect to provide fingerprints. See Davis v. Mississippi, 394 U.S. 721, 727 (1969).

50. See In re Non-Testimonial Identification Order Directed to R.H., No. 99-353, 2000 WL1234251, at *12-13 (Vt. Sept. 1, 2000) (upholding the constitutionality of a Vermont rule as applied to an order for a saliva sample on the basis of reasonable suspicion); cf. Doe v. Senechal, 725 N.E.2d 225, 231 (Mass. 2000) (holding that even if the Fourth Amendment applies to a private action for assault and battery and other torts, a court-ordered buccal swab to test whether a member of the staff of a residential treatment facility for mentally ill adolescents fathered the child of a patient is a reasonable search and seizure).

The conclusion that a court order based on probable cause (or perhaps reasonable suspicion) normally is required applies even if the police do not themselves demand or collect the DNA sample, but direct or request private citizens to acquire the sample. Suppose that shortly after an incident, a suspect goes to or is taken to a private hospital. While the suspect is still at the hospital, the police learn of the suspect's location. The police contact the hospital staff and request them to obtain a DNA sample from the suspect for law enforcement use. The private hospital would be acting as a government agent in making the intrusion and the Fourth Amendment would apply. See Skinner v. Ry. Labor Executives' Ass'n, 489 U.S. 602, 614-16 (1989). There is sufficient state action to trigger the Fourth Amendment if "the drawing of blood is instigated by the government," State v. Hardy, 963 S.W.2d 516, 523 (Tex. Crim. App. 1997), by, for instance, requesting that an emergency room doctor take a sample. Commonwealth v. Kohl, 615 A.2d 308, 310 (Pa. 1992). When the authorities intervene and request a sample even before the private entity takes one, the otherwise private entity is acting as a government agent in seizing the sample.

51. 1 National Bioethics Advisory Commission, Research Involving Human Biological Materials: Ethical Issues and Policy Guidance 13 (1999).

52. See id. at 13-15; Lawrence O. Gostin, Health Information Privacy, 80 Cornell L. Rev. 451, 464, 467-68 (1995); M. Therese Lysaught et al., A Pilot Test of DNA-based Analysis Using Anonymized Newborn Screening Cards in Iowa, in Stored Tissue Samples: Ethical, Legal, and Public Policy Considerations 3, 17 (Robert F. Weir ed., 1998); Jean E. McEwen, DNA Databanks, in Genetic Secrets: Protecting Privacy and Confidentiality in the Genetic Age 231 (Mark Rothstein ed., 1997).

53. When the police obtain a sample directly from a private citizen, there is undeniably sufficient state action to bring the Fourth Amendment into play. E.g., In re J.W.K., 583 N.W.2d 752, 754-56 (Minn. 1998); State v. Binner, 886 P.2d 1056, 1057-58 (Or. Ct. App. 1994). The extent of the government involvement is the same whether the motivation of the police is to obtain the sample to add to a database or to acquire an evidential sample to be compared to a database.

54. United States v. Pervaz, 118 F.3d 1, 6 (1st Cir. 1997); United States v. Reed, 15 F.3d 928, 931 (9th Cir. 1994); State v. Grant, 620 N.E.2d 50, 60 (Ohio 1993); State v. Maxfield, 125 Wash. 2d 378, 384, 886 P.2d 123, 127 (1994), rev'd on other grounds, 133 Wash. 2d 332, 945 P.2d 196 (1997).

56. Id. at 113-14 (quoting Walter v. United States, 447 U.S. 649, 662 (1980)); see also Coolidge v. New Hampshire, 403 U.S. 443, 488 (1971); Burdeau v. McDowell, 256 U.S. 465, 475 (1921); Tims v. State, 711 So. 2d 1118, 1122 n.2 (Ala. Crim. App. 1997) (finding "no state involvement"); People v. Perlos, 462 N.W.2d 310, 315 (Mich. 1990) (same); State v. Nelson, 941 P.2d 441, 445 (Mont. 1997) (same); State v. Enoch, 536 P.2d 460, 461 (Or. Ct. App. 1975) ("[I]f an independent private citizen finds evidence and turns it over to the police, the evidence is legitimate."); State v. Guido, 698 A.2d 729, 733 (R.I. 1997) (finding "no state action").

57. If the medical provider or researcher were uncooperative, the authorities could resort to compulsory process such as a subpoena. See, e.g., United States v. Dionisio, 410 U.S. 1, 10-11 (1973) (stating that "a grand jury subpoena to testify is not that kind of governmental intrusion on privacy against which the Fourth Amendment affords protection, once the Fifth Amendment is satisfied," but recognizing that "[t]he Fourth Amendment provides protection against a grand jury subpoena duces tecum too sweeping in its terms 'to be regarded as reasonable" '); State v. Fears, 659 S.W.2d 370, 375-76 (Tenn. Crim. App. 1983) (requiring only a showing that the object of the subpoena is logically relevant to the subject matter of a legitimate criminal investigation).

58. The condition is fulfilled if, before the government's request, the private parties acted on their "own initiative" and out of an "independent" medical or research "motivation." State v. Comeaux, 818 S.W.2d 46, 50 (Tex. Crim. App. 1991).

DNA TYPING: EMERGING OR NEGLECTED ISSUES

Edward J. Imwinkelried*
D.H. Kaye **

DNA TYPING: EMERGING OR NEGLECTED ISSUES

Edward J. Imwinkelried* D.H. Kaye **

Edward J. Imwinkelried*
D.H. Kaye **