DH Kaye: NCFDNA Report

A Report to the Working Group
on Legal Issues,
National Commission
on the Future of DNA Evidence

This report is current as of February 2, 2000. There have been significant legal developments since then. The report was to have been included in the publications of the Commission available at http://www.ojp.usdoj.gov/nij/dna/pubs.htm, but as of May 22, 2003, there was no reference to it there.

* Regents' Professor, Arizona State University College of Law; Fellow, Center for the Study of Law, Science, and Technology, 480 966-2922; k@asu.edu.

     1. Novel scientific methods
     2. Proficiency test records
          a. Proficiency testing as a prerequisite to admission
          b. The admissibility of errors on proficiency tests
          c. The use of proficiency tests to modify random-match probabilities
          d. The opportunity to retest as a response to defense arguments about proficiency testing

     1. Methods of extracting samples
     2. Offenses included
     3. Permissible uses
          a. Criminal investigations
          b. Civil litigation
          c. Research
     4. Security and sample retention

DNA has been used with great success to investigate crimes in which traces of blood, saliva, semen, hair, or other biological material are available, to convict the guilty and to exonerate the innocent. This report examines selected legal issues that arise when DNA is employed in the investigative and adjudicatory phases of the criminal justice system.

Part I discusses constitutional issues posed when the government uses DNA evidence in investigating a crime. It focuses primarily on methods of acquiring DNA from an individual suspected of committing the crime. Comparing such DNA with traces found at the scene of crime might exonerate the suspect, or it might associate the suspect with the crime.⁽¹⁾ Part I discusses 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.⁽²⁾ 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 protections.

Part I also considers a second investigative use of DNA--"profiling" 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, and Part I concludes that investigators can use genetic data in this way without infringing any constitutional rights.

Part II concerns 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.

Part III deals with law enforcement DNA databases. Querying a database derived by analyzing DNA from large numbers of people and from many crime scenes offers law enforcement authorities a powerful tool with which to identify the perpetrators of certain types of crimes. Part III explores constitutional and ethical questions that must be confronted in establishing and operating DNA databases for law enforcement purposes. It also indicates the array of policy choices that must be made in developing these systems--from the determination of which individuals are subject to having their genotypes placed in the databank, to the specification of how the DNA samples are obtained, to the decision as to how long the samples should be retained, and to the enumeration and definition of the uses to which the information may be put.

Traditionally, DNA has been used to link a suspect to a crime. When a suspect's DNA matches the DNA left at a crime scene, for example, one inference is that the suspect is the source of the crime-scene DNA.⁽³⁾ Inversely, when the DNA does not match, the suspect can be excluded as the source of the crime-scene DNA. If trace evidence is to be used to exclude and include individuals as viable suspects, the police must secure samples of DNA from individuals who might have committed the crime under investigation.⁽⁴⁾ 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, or they can take a sample with the consent of the individual. As a matter of constitutional law, the principal constraint⁽⁵⁾ on such government action is the search and seizure clause of the Fourth Amendment to the United States Constitution,⁽⁶⁾ which reads:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrant shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

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.⁽⁷⁾ As a general rule, police will need a warrant or comparable court order issued by a judge or magistrate who is persuaded that there is probable cause to believe that the DNA sample will produce evidence linking the suspect to the crime.⁽⁸⁾ With such authorization, police can use necessary force to extract the biological material.⁽⁹⁾

In some circumstances, however, either a warrant or probable cause might not be essential. For instance, if a person is legitimately under arrest, the seizure of the person is justified,⁽¹⁰⁾ and routine, non-invasive DNA sampling of all arrestees for the purpose of creating a record of the true identity of the individual is probably constitutional.⁽¹¹⁾ Furthermore, once the government has acquired the sample consistently with the Fourth Amendment, the search and seizure clause does not bar its use for another purpose.⁽¹²⁾ Exigent circumstances also could justify the absence of a warrant.⁽¹³⁾

It also is possible that an order compelling a person to give a sample could be issued on something less than probable cause. In dictum in Davis v. Mississippi,⁽¹⁴⁾ the Supreme Court suggested 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."⁽¹⁵⁾ After Davis's fingerprints were discovered to match those lifted from the window sill, he was indicted, tried, and convicted. 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. The United States Supreme Court reversed. It 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. 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. 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,"⁽¹⁶⁾ he proceeded to write that:

It is arguable, however, that, because of the unique nature of the fingerprinting process, such detentions might, under narrowly defined circumstances, be found to comply with the Fourth Amendment even though there is no probable cause in the traditional sense . . . . Detention for fingerprinting may constitute a much less serious intrusion upon personal security than other types of police searches and detentions. Fingerprinting involves none of the probing into an individual's private life and thoughts that marks an interrogation or search. Nor can fingerprint detention be employed repeatedly to harass an individual, since the police need only one set of each person's prints. Furthermore, fingerprinting is an inherently more reliable and effective crime solving tool than eyewitness identifications or confessions . . . . Finally, because there is no danger of destruction of fingerprints, the limited detention need not come unexpectedly or at an inconvenient time.⁽¹⁷⁾

Thus, 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 of individuals for whom there is no probable cause to arrest."⁽¹⁸⁾

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.⁽¹⁹⁾ For instance, an Arizona statute 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."⁽²⁰⁾ As in this instance,⁽²¹⁾ the language of many of these statutes and court rules is broad enough to apply to DNA samples.⁽²²⁾ Although the Supreme Court has not ruled authoritatively on the constitutionality of these procedures, in Hayes v. Florida,⁽²³⁾ the Court referred approvingly to its previous statement in Davis.⁽²⁴⁾

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. At that point, 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.⁽²⁵⁾

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, could be collected without probable cause or a warrant if one accepts the theory that the individual, having exposed the material to the public, retains no reasonable expectation of privacy in it.⁽²⁶⁾

Rather than compel a person to submit to DNA sampling, police might obtain DNA data on a suspect from preexisting samples or databases. As of 1998, it was estimated that there were more than 282 million specimens of human biological materials stored in the United States, with samples from another 20 million individuals accumulating each year.⁽²⁷⁾ Such 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.⁽²⁸⁾ Although the Fourth Amendment plainly applies to police efforts to obtain samples directly from suspects,⁽²⁹⁾ the prohibition of unreasonable searches applies only to government action.⁽³⁰⁾ As the Supreme Court commented in United States v. Jacobsen,⁽³¹⁾

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."⁽³²⁾

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.⁽³³⁾ This practice would fall outside the constraints of the Fourth Amendment if (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. It often will be satisfied for medical records and tissue samples.⁽³⁴⁾ 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 can be found in Katz v. United States,⁽³⁵⁾ decided in 1967. 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. 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."⁽³⁶⁾ It 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."⁽³⁷⁾ Because the federal agents had no warrant authorizing the interception, the majority held that the search violated the Fourth Amendment. In a concurring opinion, Justice Harlan elaborated on the majority's remarks. In perhaps the most famous passage in the opinions to emanate from the Justices in Katz, 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."⁽³⁸⁾

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 a temporarily private place whose momentary occupants' expectations of freedom from intrusion are recognized as reasonable."⁽³⁹⁾

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.⁽⁴⁰⁾ 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. 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. Before trial, the defendant moved to suppress the documents. The trial judge denied the motion and admitted the evidence at trial. The defendant was convicted and later appealed. The Court of Appeals for the First Circuit reversed, holding that the banks' surrender of the records violated the defendant's Fourth Amendment rights.

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 . . . ."⁽⁴¹⁾ Since the defendant had transferred the checks and deposit slips to the bank, the defendant could not assert "ownership []or possession" as to any of the subpoenaed records,⁽⁴²⁾ 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."⁽⁴³⁾

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."⁽⁴⁴⁾ However, Justice Powell made short shrift of that argument:

The depositor takes the risk, in revealing his affairs to another, that the information will be conveyed by that person to the Government. . . . This Court has held repeatedly that the Fourth Amendment does not prohibit the obtaining of information revealed to a third party, even if the information is revealed on the assumption that it will be used only for a limited purpose and the confidence placed in the third party will not be betrayed.⁽⁴⁵⁾

Justice Powell concluded that even if the banks were "acting solely as Government agents in" transcribing and surrendering the information, there was "no intrusion upon the [defendant's] Fourth Amendment rights."⁽⁴⁶⁾

The logic of Miller is easily applied to medical samples or records. Like 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.⁽⁴⁷⁾ Nevertheless, Miller might be distinguished on at least three bases. First, the Miller Court stated that the bank records in question concerned "commercial transactions."⁽⁴⁸⁾ In contrast, a medical record can relate to far more intimate aspects of a person's life.⁽⁴⁹⁾ Recent polls indicate that the vast majority of Americans are concerned about the privacy of their medical records.⁽⁵⁰⁾

Although it seems clear that a patient has a greater privacy interest in medical records than a business or individual has in bank records,⁽⁵¹⁾ 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.⁽⁵²⁾ Most jurisdictions have enacted a general physician-patient privilege,⁽⁵³⁾ and the privilege typically encompasses not only communications in a conventional sense, but also any information that the physician gains by virtue of the examination.⁽⁵⁴⁾ However, most jurisdictions do not recognize the privilege in criminal cases,⁽⁵⁵⁾and several courts have pointed to that limitation as evidence that society is unprepared to recognize a constitutionally enforceable privacy expectation in medical records or samples. In Thurman v. State,⁽⁵⁶⁾ for instance, the Texas Court of Appeals pointed out that the medical privilege is inapplicable to criminal cases;⁽⁵⁷⁾ hence, even if the citizen has a subjective expectation of privacy, society does not recognize that expectation as reasonable in a criminal setting.⁽⁵⁸⁾ For that matter, many jurisdictions not only carve out an exception to the privilege for criminal proceedings; they go farther and require physicians to report certain types of events such as violent injuries and child abuse to the public authorities.⁽⁵⁹⁾ A few jurisdictions have enacted even more sweeping legislation, requiring hospitals to furnish blood test results to the prosecutor on request in a criminal investigation.⁽⁶⁰⁾ The limited scope of the medical privilege and reporting requirements strongly suggest that the person who is the subject of the medical record lacks a "societally-recognized," constitutionally protected privacy expectation.⁽⁶¹⁾

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. Again, it seems plausible to argue that there is a more intense privacy expectation in the sample than in the records reflecting the results of a test of the sample. The sample represents a greater threat to privacy in that its existence would permit further testing and the revelation of information in addition to that already contained in the record. 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.⁽⁶²⁾ Also, in upholding subpoenas, courts occasionally stress that the records in question were "made [and] kept . . . by the hospital"⁽⁶³⁾ or that the records were not "personal papers created or kept by" the defendant,"⁽⁶⁴⁾ 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.⁽⁶⁵⁾ In Miller itself, 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.⁽⁶⁶⁾ Financial statements prepared by a bank are like medical records prepared by a hospital or laboratory, and checks and deposit slips from the depositor are like 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, in Miller, the defendant "voluntarily conveyed" the information to the banks,⁽⁶⁷⁾ but the voluntariness of providing tissue samples might be questioned. In People v. Perlos,⁽⁶⁸⁾ a leading case 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 . . . .⁽⁶⁹⁾ Nevertheless, the majority relied on Miller to upheld 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.⁽⁷⁰⁾

When a conscious person in need of medical treatment is admitted to a hospital, the patient consents to treatment⁽⁷¹⁾ 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."⁽⁷²⁾ Given the rules of medical ethics, 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."⁽⁷³⁾

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. Although a minority of cases reject this conclusion,⁽⁷⁴⁾ sometimes on dubious grounds,⁽⁷⁵⁾ and although Miller itself has been the target of much criticism,⁽⁷⁶⁾ 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.⁽⁷⁷⁾ The same is true, even more clearly, of laboratory findings or medical records involving the samples.⁽⁷⁸⁾

In addition to compelling individuals to submit DNA samples or to acquiring samples indirectly from medical care providers or researchers, the authorities might simply ask a suspect to provide them with 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.⁽⁷⁹⁾ 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.⁽⁸⁰⁾ However, in 1966, the Court mandated in Miranda v. Arizona⁽⁸¹⁾ 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. In particular, police must advise a suspect of the right not to remain silent.

The Court has taken a different approach to waivers of the Fourth Amendment right to be free from unreasonable searches and seizures. In Schneckloth v. Bustamonte,⁽⁸²⁾ 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. The existence 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. In Schneckloth, the Court sharply distinguished between the Fourth and Fifth Amendment settings. The Court emphasized 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. According to the Court, concerns about the reliability of the evidence and the integrity of the factfinding process justify a more rigorous standard under the Fifth Amendment than under the Fourth.

Although the Schneckloth standard is relatively lax,⁽⁸³⁾ in some cases Fourth Amendment consent has been found involuntary. For example, in Bumper v. North Carolina,⁽⁸⁴⁾ 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."⁽⁸⁵⁾ 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. 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. The Court explained that:

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.⁽⁸⁶⁾

Under Bumper, consent to submitting a DNA sample would be involuntary if, for instance, the police gave the suspect the impression that he or she had 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"⁽⁸⁷⁾ and avoid statements that could mislead the suspect into believing that there is a legal duty to furnish the sample when there is not.⁽⁸⁸⁾

European countries have solved difficult murder cases by appealing to all local residents to submit to DNA testing.⁽⁸⁹⁾ In perhaps the largest such mass screening, 16,400 men in western Germany were tested in the hunt for an 11-year-old girl's killer. A 30-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 11-year-old girl.⁽⁹⁰⁾ In the United Kingdom alone, police have conducted 118 such "mass screens," resulting in 48 hits and seven convictions.⁽⁹¹⁾

In principle, mass screening could be used in the United States.⁽⁹²⁾ 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.⁽⁹³⁾ A consensual contact between a police officer and a citizen is neither a search nor a seizure under the Fourth Amendment.⁽⁹⁴⁾ As a legal matter, police may ask anyone and everyone to give DNA; as long as they do not engage in coercion or misrepresentation, they may collect samples for analysis.⁽⁹⁵⁾ The practice seems less likely to be effective in this country, however, since the number of residents who would choose not to cooperate could be larger. In addition, the drain on police resources in creating, what is in effect, an ad hoc database, usually would be excessive.⁽⁹⁶⁾

To help trace the flow of human populations, geneticists and anthropologists have located genetic markers that help distinguish among ancestral populations, and various genes are known to have alleles that occur predominantly in certain racial or ethnic groups.⁽⁹⁷⁾ In addition, genetic typing permits inferences as to inherited disorders and may offer clues to facial or other bodily features.⁽⁹⁸⁾ 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.⁽⁹⁹⁾ 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 suspect.⁽¹⁰⁰⁾ Race is the prototypical example.⁽¹⁰¹⁾ Imposing the death sentence on the killers of whites but not blacks would be impermissible;⁽¹⁰²⁾ 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.⁽¹⁰³⁾ 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 us to examine 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. 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. 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. 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. These reports could be in error in any given case, but if they are generally accurate, paying attention to them is not unconstitutional.⁽¹⁰⁴⁾

The government can rely on racial information in a criminal investigation because the practice does not unfairly burden any racial group.⁽¹⁰⁵⁾ 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⁽¹⁰⁶⁾ 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 uneven hand."⁽¹⁰⁷⁾ Almost without exception, permits were denied to Chinese and granted to non-Chinese. 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, it has been held that the government can record the racial information. For instance, Hamm v. Virginia State Board of Elections⁽¹⁰⁸⁾ 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.⁽¹⁰⁹⁾ The Supreme Court affirmed without discussion.

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: no group is singled out for special treatment, and no one is penalized because of hostility toward race.⁽¹¹⁰⁾ If the police make investigative use of racial information whenever that information is useful, then all racial groups are treated alike, and 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.⁽¹¹¹⁾ 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.⁽¹¹²⁾ 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.⁽¹¹³⁾ 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. Our conclusion is simply that these are policy choices to be made about a developing technology--these options are not foreclosed by the Constitution as it been construed to date.

In courts in the United States, two major standards exist for deciding whether scientific findings will be admitted into evidence: the "general-acceptance" test and the "sound-methodology" standard.⁽¹¹⁴⁾ 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.⁽¹¹⁵⁾ 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.,⁽¹¹⁶⁾ the Supreme Court held that these rules implicitly jettison general acceptance as an absolute prerequisite to the admissibility of scientific evidence. 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." 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.

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 judicial reception of DNA evidence can be divided into at least five phases.⁽¹¹⁷⁾ The first phase was one of rapid acceptance. 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."⁽¹¹⁸⁾ In this first wave of cases, expert testimony for the prosecution rarely was countered, and courts readily admitted RFLP findings.⁽¹¹⁹⁾

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.⁽¹²⁰⁾ Some scientists questioned certain features of the procedures for extracting and analyzing DNA employed in forensic laboratories, and it became apparent that determining whether RFLPs in VNTR loci in two samples actually match can be complicated by measurement variability or missing or spurious bands.⁽¹²¹⁾ Despite these concerns, most cases continued to find forensic RFLP analyses to be generally accepted,⁽¹²²⁾ and a number of states provided for admissibility of DNA tests by legislation.⁽¹²³⁾ Concerted attacks by defense experts of impeccable credentials, however, produced a few cases rejecting specific proffers on the ground that the testing was not sufficiently rigorous.⁽¹²⁴⁾ 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.⁽¹²⁵⁾ 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 of the proper application of an approved method on the particular occasion.⁽¹²⁶⁾ Whether this inquiry is properly part of the special screening of scientific methodology, however, is debatable.⁽¹²⁷⁾

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 in which many courts held that estimates of the probability of a coincidentally matching VNTR profile were inadmissible.⁽¹²⁸⁾ 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.⁽¹²⁹⁾ A heated debate on this point spilled over from courthouses to scientific journals and convinced the supreme courts of several states that general acceptance was lacking.⁽¹³⁰⁾ A 1992 report of the National Academy of Sciences proposed a more "conservative" computational method as a compromise,⁽¹³¹⁾ and this seemed to undermine the claim of scientific acceptance of the less conservative procedure that was in general use.⁽¹³²⁾

In response to the population-genetics criticism and the 1992 NAS report came an outpouring of 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.⁽¹³³⁾ In the corresponding fourth phase of judicial scrutiny of DNA evidence, the courts almost invariably returned to the earlier view that the statistics associated with VNTR profiling are generally accepted and scientifically valid.⁽¹³⁴⁾

The fifth phase of the judicial evaluation of DNA evidence is well underway. As results obtained with the new PCR-based 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.⁽¹³⁵⁾ Sometimes, the answer will be obvious even without an extensive pretrial hearing,⁽¹³⁶⁾ and the opinions are practically unanimous in holding that the more commonly used PCR-based procedures satisfy these standards.⁽¹³⁷⁾

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.⁽¹³⁸⁾ 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.⁽¹³⁹⁾

Having discussed the importance of studies validating new DNA technologies in determining the admissibility of evidence obtained through these technologies, we turn to a different type of study--namely, a study of the proficiency of the laboratory conducting the test. In a validation study, the researchers empirically verify the ability of the technology to identify features of DNA molecules. In a proficiency study, the focus is on how competently the laboratory's analysts apply a technology that already has been validated.⁽¹⁴⁰⁾ 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 should be a prerequisite to the admission of evidence from a forensic laboratory,⁽¹⁴¹⁾ that proficiency test results should be admissible to show how likely it is that the laboratory erred in the test at bar,⁽¹⁴²⁾ and that random match probabilities should be inadmissible unless they are combined with proficiency test results to estimate the probability of a false match. And, 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, it could be argued that the prosecution should be permitted to present testimony that the defense has not retested or even requested the opportunity to retest the samples.⁽¹⁴³⁾

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.⁽¹⁴⁴⁾ 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.⁽¹⁴⁵⁾

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. 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."⁽¹⁴⁶⁾ Some courts then held that when the prosecution introduces testimony about the probability of a coincidentally matching profile, the defendant is entitled to introduce testimony about the laboratory's proficiency tests.⁽¹⁴⁷⁾ 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.⁽¹⁴⁸⁾

In contrast, in a report published in 1996, a second committee of the National Academy declined to take a position on whether evidence of laboratory error rates, as estimated from proficiency studies, should be admissible at trial.⁽¹⁴⁹⁾ 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."⁽¹⁵⁰⁾ It adds that even a test of the same laboratory might be outdated, since the laboratory may have taken corrective action.⁽¹⁵¹⁾ 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 dangers of prejudice, confusion of the issues, or undue consumption of time.⁽¹⁵²⁾

A further objection is that the testimony represents inadmissible character evidence.⁽¹⁵³⁾ If the theory of logical relevance is 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.⁽¹⁵⁴⁾ It is precisely the theory of logical relevance generally banned by Federal Rule of Evidence 404.⁽¹⁵⁵⁾ 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 proof of character.⁽¹⁵⁶⁾

This issue is rarely recognized in the trial court,⁽¹⁵⁷⁾ but it is difficult to see how a trial judge could 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 would need to be altered to give the trial court the discretion to admit the evidence.

In some circumstances, however, proficiency tests of the laboratory involved in the case will be 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. Evidence that spurious peaks or bands have occurred under similar circumstances in proficiency tests on known samples would lend support to the defense theory that the band in the pending case is an artifact. In this situation, proficiency test data are relevant because they provide information about the operating characteristics of the DNA test at that particular laboratory.⁽¹⁵⁸⁾

The third suggestion relating to proficiency testing is that random-match probabilities should be inadmissible unless accompanied by or blended with the laboratory's error rate.⁽¹⁵⁹⁾ The 1996 committee observed that combining the two figures "would deprive the trier of fact of the opportunity to separately evaluate 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."⁽¹⁶⁰⁾ The committee took the position that "a calculation which combines error rates with match probabilities is inappropriate."⁽¹⁶¹⁾ The reasoning supporting the committee's position essentially sounds under Federal Rule of Evidence 403.⁽¹⁶²⁾ 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 probabilities 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.⁽¹⁶³⁾ 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.⁽¹⁶⁴⁾

d. The opportunity to retest as a response to defense arguments about proficiency testing

The fourth suggestion related to proficiency testing has been made by prosecutors. This suggestion is that when the defense is allowed to introduce evidence of proficiency tests of the laboratory employing the prosecution 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 expert.

The testimony would be logically relevant on several theories. To begin with, if a defense expert testifies that the laboratory result is untrustworthy, it 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.⁽¹⁶⁵⁾ Inasmuch as replication is a crucial and common feature of scientific inquiry,⁽¹⁶⁶⁾ 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.⁽¹⁶⁷⁾

The 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 subject for cross-examination.⁽¹⁶⁸⁾

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.⁽¹⁶⁹⁾ 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. Again, the inference may be debatable, but the standard of relevance, particularly on cross-examination, is lenient.

Third, whether or not a defense expert discusses proficiency tests, the prosecution could argue that the defense failure to retest (or to request a retest) amounts to an admission by conduct by the defendant.⁽¹⁷⁰⁾ 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.⁽¹⁷¹⁾ 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.⁽¹⁷²⁾

In short, there are reasonable arguments for permitting the prosecution 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.⁽¹⁷³⁾ To reinforce the allocation of the burden to the government, some courts generally forbid prosecution comment on the defense failure to produce evidence.⁽¹⁷⁴⁾ 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.

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 information from the defendant, such as the defendant's mental or physical condition.⁽¹⁷⁵⁾ The Advisory Committee Note to draft Federal Rule of Evidence 503 endorsed the application of the attorney-client privilege to experts,⁽¹⁷⁶⁾ 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.⁽¹⁷⁷⁾ 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.⁽¹⁷⁸⁾ 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.⁽¹⁷⁹⁾

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,⁽¹⁸⁰⁾ 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.⁽¹⁸¹⁾ Consequently, it might be justifiable to apply the attorney-client privilege to a defense expert's 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 misanalyzed 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 failure to retest.

The power of DNA evidence has promoted proposals to create an exception to the statute of limitations for sexual assault when DNA profiling links the suspect to the assault.⁽¹⁸²⁾ However, devising a workable "DNA exception" that would respect the interests of defendants and society in defining a point after which litigation no longer can be commenced is a formidable challenge.⁽¹⁸³⁾

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.⁽¹⁸⁴⁾ Thus, the Supreme Court has described statutes of limitations as "the primary guarantee against bringing overly stale criminal charges."⁽¹⁸⁵⁾ 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.⁽¹⁸⁶⁾

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,⁽¹⁸⁷⁾ 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 if 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--and proof of that fact 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.

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.⁽¹⁸⁸⁾ 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.

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 uncontestable 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 while opposing an extension of the statute of limitations. The time limitation on post-conviction appeals of convictions and the statute of limitations for prosecutions are not symmetrical with respect to DNA evidence.⁽¹⁸⁹⁾

Few statutes prescribe the method of collecting DNA samples.⁽¹⁹⁰⁾ Most statutes provide for flexibility as to the origin of the DNA, referring to such materials as "a blood or tissue sample,"⁽¹⁹¹⁾ "a blood, tissue, or hair follicle sample,"⁽¹⁹²⁾ "a body fluid or tissue sample,"⁽¹⁹³⁾ or simply "[a]ny biological sample containing DNA."⁽¹⁹⁴⁾ However, a few states use narrower phrasing. The California law, for example, insists on "two specimens of blood [and] a saliva sample."⁽¹⁹⁵⁾ The table below lists the number of state statutes referring to various types of sample material:

SAMPLE MATERIAL	NUMBER OF STATES
blood	39
saliva	6
tissue	13
oral	1
body fluid	5
other samples necessary	1
other biological samples	2
any biological evidence	2
human biological specimen	2
scientific biological sample	1
hair follicle	2
buccal cells	1
body fluids	1

Table 1. Types of Biological Samples
for Collecting DNA for State Databanks⁽¹⁹⁶⁾

To encourage the use of the least invasive and most cost-effective collection methods, a legislature might wish to avoid being overly restrictive in defining the types of DNA-bearing biological samples that may be used.

Perhaps the most obvious question in the design of a compulsory databank is whose DNA should be taken. The trend is toward increased coverage. All states require convicted sex offenders to give samples, 36 include murder as a qualifying offense, 27 reach assault and battery, and a minority include other felonies such as kidnapping, burglary, and robbery.⁽¹⁹⁷⁾ At least five states demand samples from all felons.⁽¹⁹⁸⁾ In these jurisdictions, activities such as sodomy, prostitution, and racketeering can result in inclusion in the state databank.⁽¹⁹⁹⁾

Deciding whose DNA should be included in a database is not a simple matter. There are two possible rationales for limiting DNA databanking to offenders in the first place. One is that convicts do not deserve the same level of privacy protection as other citizens.⁽²⁰⁰⁾ This rationale applies to all felons, but the premise that conviction or even imprisonment works a loss of all privacy rights is dubious.⁽²⁰¹⁾ Prisoners do not have the same privacy as individuals who are not serving a criminal sentence: their mail, their telephone conversations, their living quarters, and even their bodies are subject to government inspection.⁽²⁰²⁾ But such searches are justified by the need to run a penal institution, not by the theory that a convict automatically forfeits all civil rights. A more convincing justification for targeting offenders as opposed to all citizens, and for choosing among the classes of offenders, therefore is needed.

Thus, the second rationale for focusing on offenders looks to a pragmatic consideration. The argument is that prior offenders are significantly more likely than non-offenders to commit some crimes that often produce biological trace evidence.⁽²⁰³⁾ This recidivism argument is more complex than folk wisdom like "Once a thief, always a thief," would suggest. To decide which crimes meet this condition, we must consider not merely whether a particular offense tends to be repeated, but whether the commission of any given offense is associated with the commission of any of the offenses for which biological evidence tends to be available. Some notation is helpful in formulating the recidivism argument clearly. Let C stand for a "collection crime" -- one for which DNA can be collected from the offender. Let T stand for a target, or traceable, offense -- one for which biological trace evidence might be found. The predictivist argument requires that the probability that a person guilty of one instance of C will commit (or has committed)⁽²⁰⁴⁾ a target crime T must exceed the probability that a person who has not committed any instance of C will commit (or has not committed) T. In symbols,

where P is a probability, the vertical line means "given," and the hyphen stands for "not." In other words, C must be a risk factor for T: individuals who possess C (a conviction for a collection offense) must be at greater risk for committing a target offense T than people who are not guilty of C.

Not long ago, it was thought that the only plausible target offense was forcible rape. In 1992, a committee of the National Academy of Sciences thought that:

[I]t is clear that crimes of most types will not afford the opportunity to recover relevant biological that will allow the police to identify an unknown suspect--i.e., the perpetrator's own body fluids. They include larcenies, burglaries, and assaults, for which ordinary fingerprints for which ordinary fingerprints are frequently found. They major exception is rape, for which semen samples can be recovered in many cases . . . . [ś] A DNA profile databank would thus be valuable primarily in investigating forcible rape . . . .⁽²⁰⁵⁾

Moreover, the committee apparently assumed that rapists rarely commit other crimes, for it suggested that the only collection crimes for rape should be sex offenses.⁽²⁰⁶⁾

This narrow view of the target and collection crimes is untenable. First, the rapid development of and experience with forensic DNA technology has shown that the notion that rape is the only realistic target crime to have been shortsighted. By 1999, the United Kingdom's Forensic Science Service was reporting a 5% chance of developing a DNA profile for property crimes.⁽²⁰⁷⁾ Although one in twenty might not seem like a large fraction, property crimes are more common than other crimes. Consequently, most of the hits in the database for England and Wales now come from burglary and vehicle theft cases rather than from rapes or murders.⁽²⁰⁸⁾

As for collection crimes C, the assumption that only convictions for sex crimes are predictive of forcible rape always has been questionable. Studies show that convicted rapists released from prison are more likely to be re-arrested for crimes other than rape than they are for another rape. The Bureau of Justice Statistics examined the arrest records of a representative sample of all prisoners released in 1983 from prisons in eleven states.⁽²⁰⁹⁾ During the three-year follow-up period, 7.7% of the 2,214 released rapists were re-arrested for another rape, but over five times this number (42.8%) were rearrested on other charges.⁽²¹⁰⁾ Apparently, rapists do not confine their criminal activities to rape.

Even so, if rapists were an insignificant proportion of the criminal population, it would not follow that a large proportion of individuals who are convicted of other crimes than rape have committed or will commit rapes. Although this situation is conceivable, rapists seem to constitute a substantial fraction of all incarcerated felons.⁽²¹¹⁾ Thus, there is reason to think that including non-sex offenders in databases would yield a meaningful number of additional hits in rape investigations.

Other data confirm this surmise. The Bureau of Justice Statistics examined the conviction histories of offenders serving time in state prisons for rape or sexual assault as of 1994. Its report suggests that persons serving time for sexual offenses were some four times more likely to have been convicted previously of non-sex crimes than of other sex crimes.⁽²¹²⁾ Furthermore, jurisdictions that have expanded their databases report matches between trace evidence samples in rape cases and databank samples from men convicted of burglary⁽²¹³⁾ and aggravated assault.⁽²¹⁴⁾

In sum, even with respect to the single target crime of rape, many offenses are plausible candidates for collection crimes. And, as we have seen, rape is hardly the only justifiable target crime. Trace samples of DNA can assist in solving nonviolent property crimes as well as crimes like assault and murder that can involve transfers of body cells from a victim to an attacker, or vice versa.

Of course, with respect to all the target offenses, the question of whether a prior conviction for a collection offense is indeed a risk factor remains. Data showing that individuals with a history of collection crimes C are more likely to commit a new target crime T than are individuals with no such history to commit such a crime are not readily available. But recidivism rates for many offenses are known to be high--much higher than one would expect the rate of new offenses to be in the general population. In the Bureau of Justice Statistics follow-up study, for example, the rates of re-arrests and re-convictions for rapists were 52% and 36%, respectively. For all violent offenders, the rates were still higher--60% and 42%, respectively.⁽²¹⁵⁾ But the most direct evidence of the value of expanding the range of collection crimes well beyond sexual assault comes from states that have been collecting DNA from many types of criminals since the early 1990s. In Virginia, 60% of all database hits have come from convicted burglars; in Florida, the figure is about 50%.⁽²¹⁶⁾

This is not to say that every state should extend its collection offenses to reach or all, or even most, crimes. As stated at the outset, the coverage issue is not simple. That question requires some evaluation of the marginal costs and benefits of creating and maintaining larger databases, and there is a paucity of data on these matters. We are dealing in probabilities both as to the recurrence of crime and the depositing of DNA, and with a criminal justice system in which the multiplicity of crimes and the practice of plea bargaining can result in very different types of convictions for the same conduct. In addition, the deterrent impact of DNA databases is exceedingly difficult to quantify.

Since the purpose of creating offender databases is to identify the perpetrators of new or previously unsolved crimes, law enforcement personnel must have access to it for the purpose of ascertaining whether trace evidence samples match any records in the database. But the data or samples might be used in other ways as well. For example, retesting certain samples might be useful for quality control and assurance purposes. Statistical research with offender data could produce more accurate estimates of the frequencies of the alleles and genotypes used for identification.⁽²¹⁷⁾ These uses are closely tied to the raison d'ętre of the databanking system--identification of the perpetrators of crimes. But there are other possible uses as well. The data might assist in the identification of missing persons or the victims of major accidents or disasters. They might be employed in certain civil cases, such as paternity actions, in which the genotype of an individual who is not available for DNA testing is on file. Finally, it is conceivable--though far from clear--that a large enough collection of samples might have some value in studying the genetics of some behavioral traits.⁽²¹⁸⁾

Given the variety of uses to which DNA samples might be put, database statutes should enumerate clearly the uses that are permissible. This section surveys the possible uses to which law enforcement databanks or databases might be dedicated.

Naturally, all offender database statutes authorize the DNA samples and records in the databank to be used in criminal investigations to identify the perpetrators of crimes.⁽²¹⁹⁾ As a Texas statute explains, "[t]he principal purpose of the DNA database is to assist federal, state, or local criminal justice or law enforcement agencies in the investigation or prosecution of . . . offenses in which biological evidence is recovered."⁽²²⁰⁾

In performing this core task, it is possible that a database search might implicate an offender's relatives rather the previously convicted offender himself. For instance, if the closest thing to a complete match is a match at 12 out 13 loci, then everyone in the database is excluded, but it is exceedingly likely that the trace evidence DNA comes from a full sibling of the individual who matches at the 12 loci.⁽²²¹⁾ The possibility that a relative might be incriminated as a result of a partial match, it could be argued, invades the relative's genetic privacy and thus makes DNA databanking improper or unreasonable under the Fourth Amendment.⁽²²²⁾

The argument dissolves under analysis.⁽²²³⁾ It is true that the relative might not have been suspected but for the database search, but the search does not violate any cognizable privacy right of the relative. Relatives, like other individuals, have no right to be free from legitimate investigation just because suspicion is triggered by information obtained from another person. Suppose a rape victim studying mugshots states that the face in one of the photographs is very similar to the perpetrator's, but the rapist was "somewhat older." The police happen to know that the person depicted in that photograph has an older brother. Could the older brother object to his becoming a target of the investigation because he did nothing that caused his younger brother's picture to be in the police files? As with the mugshot, if a DNA sample is properly obtained, there is no reason to prohibit its use as an investigative lead to a relative.

Although there is no direct case law on this question, a well-settled Fourth Amendment doctrine supports the conclusion that it would not violate the relative's constitutional rights for the police to follow up on the partial match.⁽²²⁴⁾ The doctrine is that of "plain view."⁽²²⁵⁾ When evidence comes into the plain view of police who are lawfully in place, the state may use that evidence.⁽²²⁶⁾ Here, the police are conducting a lawful DNA database search, and that search yields a partial match.⁽²²⁷⁾

A variation on the claim that the privacy of relatives is invaded by examining the identifying loci of samples in a database posits a prime suspect who has fled the jurisdiction or is otherwise unavailable for DNA testing but who has close relatives in the database. "In this kind of situation," it has been said that "law enforcement officials may argue that it is necessary to compare the DNA of this prime suspect's close biological relatives to that of the DNA artifact [sic] from the crime scene to determine whether to continue or cease pursuit of the suspect."⁽²²⁸⁾ However, the relatives who are legitimately in the database can hardly complain that the state should not be able to compare the crime-scene DNA with all the profiles stored in the database. And, for the reasons already given, neither can the individual who already is "the prime suspect."

In sum, the constitution does not compel any limitations on database searches that might implicate relatives on the ground that the privacy of the relatives is threatened. Neither it is apparent that any sound policy would be served by creating such limitations.

Most statutes do not limit the databanks to the investigation of criminal cases.⁽²²⁹⁾ Another commonly authorized use is the identification of human remains⁽²³⁰⁾ or missing persons.⁽²³¹⁾ Of course, in many circumstances, these investigations can be considered criminal in that they are used to determine whether criminal misconduct is involved, but in cases of mass disasters and certain other situations, the identifications may not be part of the criminal process. Nevertheless, many jurisdictions denominate them an allowable, "humanitarian" use.⁽²³²⁾ Indeed, a few states permit data from "close biological relatives" of missing persons to be included in the state system.⁽²³³⁾ Some states specifically allow the information in the database to be used, pursuant to a court order, in proceedings establishing parent-child relationships,⁽²³⁴⁾ if not in any civil case.⁽²³⁵⁾

The use in missing-person investigations or parentage proceedings has been characterized, somewhat disparagingly, as "familial surveillance."⁽²³⁶⁾ However, where civil discovery mechanisms could be employed to compel the person whose DNA is desired to provide a sample, obtaining a pre-existing sample of DNA would not seem to violate any overriding privacy interest.

DNA databanking statutes typically allow the data on the genotypes of convicted offenders or the associated samples to be used in certain kinds of research. Arguably, merely authorizing sample collection for "law enforcement identification purposes"⁽²³⁷⁾ would permit the information to be used for research into the forensic allele and genotype frequencies, and it would allow the samples to be used for quality control or assurance. Many statutes also explicitly provide for this, usually on the condition that the samples or data be "anonymous"⁽²³⁸⁾ or stripped of "identifying information."⁽²³⁹⁾ Still other statutes authorize "identification research and protocol development of DNA forensic methods"⁽²⁴⁰⁾ It also could be argued, albeit with some difficulty, that the provisions speaking of "law enforcement purposes" or "humanitarian purposes" would countenance releasing samples for research into possible genetic influences on crime or violence.⁽²⁴¹⁾

A few observers have contended that any research use of any person's DNA samples without the person's consent is unethical or illegal.⁽²⁴²⁾ But even in the usual medical research context, the propriety of the research use of archived tissue samples is a more complex matter than these uncompromising pronouncements seem to recognize. The traditional understanding of the ethical limits on research with human subjects is considerably more open to the use of archival data and specimens in medical, epidemiological, and health services studies--even without consent.⁽²⁴³⁾ In any event, DNA samples in convicted-offender databases are different from tissue samples stored in hospitals or research laboratories. For law enforcement samples, there is no issue of consent in the first place. A patient has a right, grounded in personal autonomy, to decline to donate tissues to medical research.⁽²⁴⁴⁾ But where a patient can refuse to have the tissues removed at all, a prisoner convicted of a collection crime has no choice--the law demands that he supply a sample of DNA. The samples can be acquired legitimately for a public purpose without regard to the desires or wishes of the "donors," because there is no moral or legal obligation to honor their wishes over the benefits that DNA databanking offers society. Unless a further research use of the samples poses some risk of harm to the individuals who are compelled to donate their DNA, the usual foundation for the supposed need for consent is weakened.⁽²⁴⁵⁾ Consequently, if anonymizing the data or samples is sufficient to protect the individual sources of the DNA from stigmatization or any other harm from the research, then securing the consent of the offenders may not be essential.

If there is no legal categorical imperative that precludes the use of offender DNA samples for research, the issue remains one that legislators should resolve in light of the balance of individual and public interests. Statistical research into the distributions of biometrically useful alleles or genotypes in the convicted offender populations would seem to pose no risk to anyone and at least some benefit to forensic science. Studies of the quality of laboratory performance also can be beneficial and cannot harm individual interests. Although a state might choose to conduct such research with other DNA sources, the use of offender data or samples is directly connected to operating and administering an offender DNA databanking system, and it is not surprising that many statutes permit the use of a convenient source of DNA for this research.

Although nonoperational research lacks the same nexus to the databanking system, it is not necessarily impermissible for that reason. If medicine or science stood to make major gains by reason of these samples and if there could be no harm to the individuals from whom the samples originated, then the case for a broad research-use provision would be clear. But neither any great public gain nor any grave private loss is apparent. Tissue samples linked to comprehensive health records are valuable for biomedical research; DNA samples from convicted offenders are of little importance in themselves. It is possible that some researchers would be interested in acquiring the samples to trawl for associations between offenses and alleles. But the utility of convicted offender samples for such research in behavioral genetics is unclear for two major reasons. First, unlike most diseases, the behaviors associated with these samples are not well-defined. Certainly, the notion that there is a gene or set of genes for "crime" seems naive at best. Researchers in this field speak of genetic predispositions toward broadly defined behaviors such as "novelty seeking," which "can be expressed in many different ways" and are not strictly determined by a single gene or even a set of interacting genes.⁽²⁴⁶⁾ Second, even if specific categories, such as pedophilia, might merit investigation, offender databanks, which merely contain samples from unrelated individuals, would be of limited value in genetic linkage studies.⁽²⁴⁷⁾ Thus, the scientific case for access to the samples often will be weak.

On the other hand, to dismiss all possible research that might benefit from these samples as scientifically worthless would be dogmatic or doctrinaire. Research that can advance knowledge should be encouraged unless it poses actual dangers to the research subjects or to the public. Public concern with studies of the genetics of behavior--particularly criminal behavior--is acute. There is palpable fear that data will be misused, that tentative findings will be misrepresented as certain knowledge, and that weak correlations will be transformed into powerful predictions that cannot bear the weight that will be placed upon them. The risk of misuse of knowledge is not fanciful.⁽²⁴⁸⁾ Inasmuch as the lay perception of the extent to which we are puppets of our genes far outstrips any scientific reality, research findings about genetic influences on behavior could assume a social importance that they do not merit.⁽²⁴⁹⁾

One response is to avoid knowledge that might be misused. But another is to encourage the scientific community to pursue all methodologically sound research into reasonable hypotheses and to rely on public discourse and debate to place the research results in their proper context. The argument that research into the bases of behavior should be impeded because findings about genes might be misused comes perilously close to a policy of censorship of unwanted discoveries of genetic components of complex human behavior.

Of course, not every possible research use deserves accommodation, and legislatures that choose to allow nonoperational research uses would do well to consider procedures for ensuring that the proposed research respect the rights of the subjects and the interests of the public. For example, one might require that no DNA samples or data be provided to genetics researchers unless their research has been approved by an institutional review board charged with assessing its scientific merit and its risks to human subjects.⁽²⁵⁰⁾ Since no existing, let alone immutable, rule of law altogether precludes this type of research, such matters have to be resolved as policy choices by American society.

Delineating the permissible uses for the DNA used to create offender databanks is one thing; ensuring that the actual uses will correspond to the permitted ones is another. Both public policy and constitutional doctrine militate in favor of meaningful protections against unauthorized uses or disclosures of samples or records, and most statutes do strive to curtail dissemination and use.⁽²⁵¹⁾ Although even the best security systems and the threat of criminal penalties cannot assure that misuse never will occur,⁽²⁵²⁾ the level of security is considerably higher than that sometimes surrounding DNA samples in the private sector.

Combined with a physically secure system, most statutory protections probably satisfy constitutional requirements. In Whalen v. Roe,⁽²⁵³⁾ the Supreme Court rebuffed a constitutional attack on a database containing information that was indisputably "personal in character and potentially embarrassing or harmful."⁽²⁵⁴⁾ The database, maintained by the New York Department of Health, consisted of copies of all prescriptions for certain dangerous drugs. The medical information, including the name and address of each patient, was entered into a computerized data base. The Court deemed the combination of (1) a "statutory or regulatory duty to avoid unwarranted disclosures,"⁽²⁵⁵⁾ (2) physical measures to ensure security, and (3) a history of operation that had not been marked by breaches of confidentiality, adequate to satisfy the interest of patients in the privacy of their prescriptions.⁽²⁵⁶⁾ No less should be required of a government databank of DNA samples. With sufficient safeguards--but not without them--a system for collecting DNA on arrest, analyzing it for appropriate genotypes, and storing those data for law enforcement purposes should be constitutional.⁽²⁵⁷⁾

Security beyond the constitutional minimum could be provided, however, by departing from the current procedure of retaining most samples indefinitely and by insisting that authorities analyze only those genotypes that have no more social significance than other identifying features such as skin color, eye color, fingerprint patterns, and blood and tissue types.⁽²⁵⁸⁾ These genotypes are far less sensitive or revealing than the vast array of non-genetic information that is the traditional subject of privacy protection.⁽²⁵⁹⁾ With such genotypes, the most effective form of protection against unauthorized disclosure of samples would be the automatic destruction of the samples once the identifying alleles are recorded. The result would be a database of computer-searchable--but socially trivial--numerically encoded genotypic identifiers. DNA databanking with personal identifiers would not be practiced, although anonymized samples might be retained for quality control or research purposes. This, in turn, would help put to rest any fears that the government would access the DNA samples to discover disease-related information.⁽²⁶⁰⁾

An earlier report to the working group analyzed the constitutional protections implicated by laws requiring individuals to submit to DNA sampling at the time of an arrest. It concluded that a minimally invasive method of sampling combined with a very secure system of storing identifying information probably is constitutional. However, it did not discuss the possible need to expunge records of individuals who are not convicted of the crimes for which they are arrested. There are many reasons that a conviction might not be obtained, ranging from an unlawful arrest⁽²⁶¹⁾ to a verdict of not guilty.⁽²⁶²⁾ A state might well choose to remove the DNA sample from its databank as well as the record of the individual's alleles;⁽²⁶³⁾ or it might provide for the destruction of these materials if requested by the individual. But must it provide for such expungement?

To put this issue in perspective , we should distinguish both a different issue and a different body of law. To begin with, we must differentiate an action for expungement from a case in which the prosecution brings a citizen to trial on the charge that was the subject of the arrest and proffers an analysis of the DNA sample as evidence. In this case, the government is the moving party. The government is asking the court to receive the DNA analysis into evidence. If the arrest was unlawful, the DNA sample is inadmissible, derivative evidence. In Wong Sun v. United States,⁽²⁶⁴⁾ the Supreme Court announced that the Fourth Amendment exclusionary rule requires the suppression not only of evidence of "the primary illegality" but also of evidence "come at by exploitation of that illegality."⁽²⁶⁵⁾ When the government is the moving party and seeks the introduction of the DNA analysis, the citizen has a full-fledged federal constitutional right to have the derivative evidence suppressed. In contrast, in the fact situation now of interest, the citizen sues for the return or destruction of the DNA sample taken and included in the databank.

Moreover, we must distinguish the federal law from the corresponding body of state law. Even if the arrest is perfectly lawful, a state legislature or court has the power to authorize or require expunction of the arrest records, possibly going to the length of destroying a DNA sample taken on arrest.⁽²⁶⁶⁾ A state could do so pursuant to its own constitution, statute,⁽²⁶⁷⁾ or a court's inherent equitable power.⁽²⁶⁸⁾ When the courts resort to this equitable power, they typically balance the competing interests to determine whether to decree expungement. A court may weigh the likelihood that the retention of the arrest record will disadvantage the citizen in seeking employment or obtaining professional licensing against the extent to which record might enhance the ability of the police to identify persons with a criminal propensity.⁽²⁶⁹⁾

The states vary widely in their approach to the question of when a citizen is entitled to have his or her arrest records expunged. In a few jurisdictions, the courts are receptive to requests for expungement and absent a compelling reason to the contrary, will afford relief even when the prosecution has merely dropped charges.⁽²⁷⁰⁾ However, most states tend to take a more restrictive approach.⁽²⁷¹⁾ In some states, the citizen must show that substantial time has elapsed with no further arrests or prosecutions.⁽²⁷²⁾ In other jurisdictions, individuals who have been acquitted at trial are generally entitled to expungement.⁽²⁷³⁾ In still other jurisdictions the court may expunge the records only if it makes a "determination that the person arrested is factually innocent."⁽²⁷⁴⁾ In the most restrictive jurisdictions, the tendency is to grant relief only when the arrest itself was illegal or accompanied by another violation of constitutional rights.⁽²⁷⁵⁾ The states disagree not only over when relief is permissible but also over the form of the relief. Some jurisdiction merely segregate and seal "expunged" records; others physically destroy them.⁽²⁷⁶⁾ If the state grants the former type of relief, it might still be possible for the police, prosecutors, or courts to obtain access to the records for purposes of an investigation or prosecution.⁽²⁷⁷⁾

The issue of interest in this report, though, is whether the federal constitution would warrant granting relief to a citizen seeking expungement.⁽²⁷⁸⁾ In Davidson v. Dill,⁽²⁷⁹⁾ the Colorado Supreme Court discerned a limited constitutional right to expungement. The citizen in question had been fingerprinted and photographed on arrest. After she was acquitted, she filed suit for an order expunging her arrest records and, in the alternative, compelling their return to her. The lower court dismissed the complaint for failure to state a claim on which relief can be granted. However, the appellate court reversed. Citing Griswold v. Connecticut,⁽²⁸⁰⁾ the state supreme court invoked a "fundamental" constitutional "right of privacy."⁽²⁸¹⁾ The court declared:

We have now reached the point where our experience demands the existence of a right of privacy in the fingerprints and photographs of an accused who has been acquitted, to be at least placed in the balance, against the claim of the state for a need for their retention.⁽²⁸²⁾

However, Dill has little precedential value today. The decision, rendered in 1972, antedated the United States Supreme Court's 1976 decision in Paul v. Davis.⁽²⁸³⁾ In this case, Davis was arrested for shoplifting, but he was never brought to trial on the charge. When he was arrested, his photograph was taken. Davis alleged that the police later included the photograph in a flyer that purported to identify "active shoplifters" in the metropolitan area. Davis further alleged that the police distributed the flyer to merchants throughout the area. Davis sued the police for defamation and violation of his federal civil rights.

The Supreme Court held that the police had not deprived Davis of any constitutional right. The majority opinion treats that the right of privacy conferred by the Due Process Clause as limited to a right to autonomy in certain areas:

[O]ur "right to privacy" cases, while defying categorical description, deal generally with substantive aspects of the Fourteenth Amendment. In Roe [v. Wade, 410 U.S. 113 (1973)], the Court pointed out that the personal rights found in this guarantee of pesonal privacy must be limited to those which are "fundamental" or "implicit in the concept of ordered liberty" . . . . The activities detailed as being within this definition were ones very different from that for which respondent claims constitutional protection--matters relating to marriage, procreation, contraception, family relationships, and child rearing and education. Respondent's claim is far afield from this line of decisions. He claims constitutional protection against the disclosure of the fact of his arrest upon a shoplifting charge. None of our substantive privacy decisions hold this or anything like this, and we decline to enlarge them in this manner.⁽²⁸⁴⁾

It would be possible to limit Paul to its facts. The Paul Court noted that the case did not involve "an unreasonable [and unconstitutional] search."⁽²⁸⁵⁾ However, the language of the opinion is so sweeping and forceful that the lower federal courts have concluded that there is no constitutional privacy right to have arrest records expunged or destroyed.⁽²⁸⁶⁾ Instead, in expungement cases the federal courts rely on their inherent equity power.⁽²⁸⁷⁾ Some insist that such requests must be analyzed on a case-by-case basis.⁽²⁸⁸⁾ Other federal courts, though, have developed a general list of the situations in which they will grant expungement relief:

These lists typically include situations where the arrest was unlawful, where mass arrests rendered judicial determination of probable cause impossible, [and] where the arrest, although proper, was based upon a statute that was later declared unconstitutional . . . .⁽²⁸⁹⁾

Whatever approach the court takes, relief is usually granted only in "extreme circumstances."⁽²⁹⁰⁾ The federal courts ordinarily find such circumstances only when the arrest itself was illegal or accompanied by a constitutional violation.⁽²⁹¹⁾ Thus, in all probability a federal court would not brand a policy of retaining DNA information to be unconstitutional on its face,⁽²⁹²⁾ and it would order the destruction or return of a DNA sample taken on arrest only if the court concluded that the arrest itself was unconstitutional.⁽²⁹³⁾

Thus far, we have considered DNA databanks and databases that are designed to include only those individuals who, by reason of other contact with the criminal justice system, seem more likely than the typical citizen to be linkable through a database to past or future crimes. Such systems are "exclusive" in the sense that they seek to exclude most of the population, reserving places in the database for the individuals of most interest to the criminal justice system. A radically different approach is conceivable. "Inclusive databanking" would seek to include more--perhaps much more--of the population, without regard to the risk that any given individual ever will commit a crime. This section discusses certain legal and policy aspects of inclusive databanking.

Part I examined the Fourth Amendment law applicable to acquiring a DNA sample of a particular suspect from a private repository of tissue samples. Here, we consider the possibility of acquiring the entire private databank to expand the jurisdiction's law enforcement database.⁽²⁹⁴⁾ Would acquiring the samples for testing invade the Fourth Amendment rights of the individuals whose samples are in the private database?

For the reasons indicated in Part I, it is likely that the courts would refuse to find a constitutionally protected interest in the database samples. As we saw in that section, United States v. Miller⁽²⁹⁵⁾ holds that a person lacks a "legitimate expectation of privacy"⁽²⁹⁶⁾ in commercial, financial records provided to a bank. The expectation is diminished because the information "conveyed to the banks" is "exposed to their employees in the ordinary course of business."⁽²⁹⁷⁾ The same reasoning applies to most subpoenaed medical or laboratory samples.⁽²⁹⁸⁾ Typically, a patient or research subject who provides tissue samples agrees not only that biomedical workers may handle and analyze these samples for the patient's own diagnosis or treatment, but also for many other uses, giving access to the samples to a still larger circle of individuals.

A system that placed the identifying DNA genotypes of all newborns, immigrants, and visitors to the United States in a central location could serve to identify virtually anyone whose DNA is deposited at the scene of a crime anywhere in the United States. The case in favor of such a comprehensive DNA database for identification is straightforward.⁽²⁹⁹⁾ First, the deterrent effect of DNA databanking is greatest for a universal database. Convicted-offender databases can deter only those offenders who have been caught and convicted for previous crimes.⁽³⁰⁰⁾ By increasing the probability of detection of new and old offenders alike, a comprehensive database can do much more to reduce the rate of certain crimes. And, making apprehension more certain permits the same level of deterrence with less Draconian (and costly) periods of imprisonment.⁽³⁰¹⁾

Second, a comprehensive database avoids many problems or issues associated with offender or arrestee databanking. It obviates the need to draw some line between those offenses for which databanking is permitted and those for which it is not. It avoids any risk that police will make pretextual arrests merely to secure DNA samples. It makes it unnecessary to infer physical traits or racial or ethnic identity from trace evidence samples. Perhaps most important, it avoids stigmatizing any person or group. A comprehensive database imposes the same obligation on all racial and ethnic groups. There is a widespread perception that minorities are overrepresented in the criminal justice system in part because they are wrongfully arrested and convicted to a greater degree than whites. A universal database would help prevent wrongful convictions and arrests of minorities. When an eyewitness mistakenly concludes that the criminal was a minority member, a wrongful arrest (and conviction) can ensue. A universal, readily accessible national database would aid in preventing such arrests in subsequent miscarriages of justice.⁽³⁰²⁾

Third, a single, national database would be more efficient than a system of over 50 separate databases of offenders or suspected offenders. From this perspective, the current system of multiple, overlapping databases represents unnecessary duplication and a waste of scarce resources. For all these reasons, a single, secure, national DNA identification database is attractive.

To a greater extent than any other step the federal government could take, however, the creation of such a database raises the spectre of Big Government.⁽³⁰³⁾ I