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Supplement to Chapter 14:DNA Typing: Lingering and Emerging IssuesCopyright © 2001 DH Kaye |
The history of DNA evidence is recounted in an engaging book, And the Blood Cried Out by a former prosecutor, Harlan Levy. For a less sanguine view of that history, see Paul C. Giannelli, The DNA Story: An Alternative View, 88 J. Crim. L. & Crimin. 380-422 (1997).
The current scientific and legal issues are discussed in 3 Modern Scientific Evidence: The Law and Science of Expert Testimony ch. 25 (David Faigman et al. eds., 2002), which is a revision of David H. Kaye & George Sensabaugh, Reference Guide to DNA Evidence, in Reference Manual on Scientific Evidence (Federal Judicial Center ed. 2d ed. 2000).
Insert the following after the news story on "mass DNA screening" in Britain (p. 223):
Notes
Police in the United States have followed the British example of collecting DNA from large numbers of "volunteers" in the hope of turning up leads -- a practice that has been criticized as "DNA dragnets." [Give examples and discuss legal issues. See PBS religion and Ethics story on Charlottesville]
On the constitutionality of mass screening of members of a single race, see Brown v. City of Oneonta, 221 F.3d 329 (2d Cir. 200), and 235 F.3d 769 (2d Cir. 2000) (opinions accompanying denial petition for rehearing en banc).
There have been suggestions that acquiring blood samples from suspected terrorists (or others) to see whether they have antibodies to anthrax might be useful:
Nicholas Wade, Single-spore Theory of Anthrax Disturbs Investigators, N.Y. Times, Nov, 8, 2001NEW YORK - Investigators assigned to the case of Kathy T. Nguyen, the Manhattan hospital worker who died of inhalation anthrax last week, are confronting some disquieting possibilities as to how she may have become infected.
One, which has aroused keen interest among investigators, is that at some point in her well-ordered, fairly restricted life, she crossed paths with a perpetrator of the attacks and his product. If that is the case, reconstructing Nguyen's movements, as investigators are trying to do, may lead to the source of the spores.
But another possibility, more threatening to the public, is that Nguyen came nowhere near the person who distributed the spores or an envelope filled with them, and yet was infected anyway. If that is the case, some people may be infected by doses of anthrax spores that are much smaller than generally thought, and Nguyen may have been felled by a very few spores that she somehow happened to inhale.
Except for Nguyen, those who have contracted anthrax have had some obvious point of contact with the spore-laden letters and can reasonably be assumed to have inhaled a significant dose of spores.
But this is not the case with Nguyen. Nothing in her home or mail or place of work at the Manhattan Eye, Ear and Throat Hospital contained any trace of anthrax spores, investigators say.
Dr. Jeffrey Koplan, director of the Centers for Disease Control and Prevention, said Wednesday, "It would take a lot more than a few spores to cause exposure anthrax." And New York City investigators had previously said they were looking for opportunities Nguyen might have had to come in contact with a large quantity of spores.
But some experts believe that just a few spores, maybe even a single spore, can infect a susceptible person in rare circumstances.
Could Nguyen have breathed in a stray puff of spores wafting through Manhattan's canyons? The lethal dose for anthrax is often said to be 8,000 to 10,000 spores. But that is in fact the amount needed to kill 50 percent of a population of monkeys. No one knows the smallest number of spores it would take to kill just 1 percent of a population -- the experiment would require hundreds of monkeys -- but it could be just a couple of hundred spores.
Human lungs hold 500 million miniature compartments where the blood exchanges gases with the air. Each of the 200 spores is likely to be inhaled into a different compartment and would have an independent chance of infecting the body, said Dr. Matthew Meselson, a biologist at Harvard University. In his view a single spore has a chance, however small, of infecting someone.
The Army's chief infectious disease specialist in the Persian Gulf War, Dr. Craig E. Smith, agreed.
The idea that one spore can suffice for infection is somewhat at odds with the view often expressed by officials at the Centers for Disease Control and Prevention that there is a threshold, or cutoff number of spores, below which no infection can occur. But the one-spore theory would make more understandable a case like Nguyen's, in which no obvious route of exposure has yet come to light.
"Should we be alarmed that she's an outlier for whom no obvious connection exists?" asked Dr. Smith, who is now at the Phoebe Putney Memorial Hospital in Albany, Ga. "I do find that alarming because it implies she had a very small inoculum."
Another possible explanation for Nguyen's case is that she passed near some so far unidentified source of anthrax, like a house, office or laboratory where the anthrax spores used in the two attacks were being prepared. If the anthrax was home-grown, the responsible person is presumably someone well trained in medicine or microbiology or pharmaceutical manufacturing.
Dr. Smith said that one way of finding such a perpetrator would be to test suspects' blood for antibodies to anthrax. People brewing anthrax spores are likely either to have vaccinated themselves beforehand, or to have become sufficiently exposed to have raised antibodies even if they were taking antibiotics as protection, another expert said.
"If I'd taken 100 people into custody as potential terrorists, I would have taken a blood sample from every single one," Dr. Smith said. "If anyone came out positive that would mean they had had a natural exposure to anthrax or had been vaccinated, which I think would be evidence they had a premeditated plan to disseminate anthrax."
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said that testing suspects, like those being detained by the FBI in connection with the Sept. 11 attack, "is certainly something that is quite reasonable to consider."
"The presence of antibodies to anthrax," he added, "might indicate if these individuals had been vaccinated to protect them."
There is no sign so far that the FBI has considered screening suspect populations for the presence of anti-anthrax antibodies in their blood. An FBI spokesman dismissed the issue as "a medical question."
Federal investigators did not use the precise methods of blood testing, but instead relied on a far more subjective approach, handwriting analysis, to explore the possible connection of a man from Hamilton Township, N.J., to the three anthrax letters.
Many of the people being detained by the FBI are being held on alleged violations of immigration law, but legal experts said they had not heard of blood samples being requested from the detainees.
"I am not aware of that," said Lucas Gutentag, director of the immigrants' rights project at the American Civil Liberties Union. But he said that, given the secrecy surrounding the investigation, "Even seeking a court order to seek a blood sample would not necessarily be disclosed and could be conducted in a closed judicial proceeding."
Widespread screening of suspect populations, like the detainees, or people on the mail-collection route of the Trenton post worker who contracted anthrax, or any group that Nguyen might have met, would raise legal issues, and even a voluntary request for blood might be seen as coercive. Wide screening with DNA fingerprinting has been used occasionally in Britain.
Dr. Michael Osterholm, a bioterrorism expert at the University of Minnesota, said it was important for investigators to keep their minds open to all possibilities. Nguyen's case was "an epidemiologist's nightmare," he said, because she lived alone with few close contacts and died before she could be interviewed. This clueless landscape was made even harder to read by the long incubation period of anthrax spores, Dr. Osterholm said.
Caselaw continues to hold
DNA databanking constitutional. See Bolling v. Romer, 101 F.3d 1336, 1340 (10th Cir. 1996)
(rejecting search and seizure, self-incrimination, due process, equal protection, and
cruel and unusual punishment claims against collection and analysis of saliva samples of
sex offenders). Indeed, only one court has held a convicted offender database to violate
the constitution. In Landry v. Harshbarger, No. 98-462 (Mass.
Super. Ct. Aug. 12, 1998), the county court issued a preliminary injunction against the
enforcement of Massachusetts's databanking law on the theory that compulsory extraction of
blood without probable cause and a warrant violated the Fourth Amendment and the state's
constitution. Despite the efforts of organizations such as the Harvard Law School, Boston
College Law School, Chicago-Kent College of Law, the Council for Responsible Genetics, and
the ACLU, all of whom submitted amicus briefs, the Supreme Judicial Court of Massachusetts
vacated this order. Commonwealth v. Landry, 429 Mass. 336 (1999). Some of the arguments
about the bioethics of DNA databanking propounded in several of these briefs are
questioned in D.H. Kaye, Bioethics,
Bench and Bar: Selected Arguments in Landry v. Attorney General, 40 Jurimetrics J. 193
(2000).
The Arizona Supreme Court reversed the Court of Appeals in State v. Hummert, reasoning that an expert may testify to the uniqueness of a three-locus match even if that conclusion is not generally accepted in the scientific community. The Supreme Court read the expert testimony on this point as relying solely on personal experience, and not on scientific studies. The opinion is criticized in D.H. Kaye,
Encouraged by the NRC report and the opinion in Bloom, in November 1997, the FBI announced a policy under which its analysts may testify that a defendant is the source of DNA left at a crime scene -- under certain conditions:
Lewis Carroll's Dodo of Wonderland was such a swell old bird. When Alice and an assortment of small animals had finished running an incoherent "caucus" race to dry themselves off, they surrounded the Dodo and demanded to know, "But who has won?" The Dodo pressed a finger to his forehead, gave it a "great deal of thought" and replied, in the stirring spirit of a self-esteem coach, "EVERYBODY has won, and all must have prizes."
In real life, of course, not everybody wins, least of all the poor Dodo. A large flightless bird native to Mauritius Island, east of Madagascar, the dodo was first encountered by Europeans toward the end of the 1500s. A mere half century later, the guileless dodo was extinct, the victim of human hunters and the pigs and rats that accompanied them. And so few specimens of the bird were preserved that scientists have been arguing ever since over what sort of creature it was, what its evolutionary tale may have been and in what avian family tree it nested.
Now a team of scientists, relying on DNA extracted from the preserved dodo thought to have inspired Lewis Carroll, has confirmed one longstanding school of thought about the bird's heritage. It seems that the dodo and the closely related solitaire bird -- another flightless giant native to neighboring islands in the Mascarene chain -- are nothing but overgrown, landlubbing pigeons.
Reporting in the March 1 issue of Science, Beth Shapiro, Dr. Alan Cooper and their colleagues at the University of Oxford and the Natural History Museum in London, discuss their comparison between genetic sequences in the dodo and the solitaire, and those of 37 other species of pigeons and doves. . . .
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