“Familial searching” in law enforcement DNA databases has been pilloried as a step “towards eugenics and corruption of blood” and “lifelong genetic surveillance” that is “inconsistent with a basic pillar of American political thought.” Courts have yet to address the issue fully, but several commentators contend that the practice is unwise, unjust, or unconstitutional. This Article examines the more significant constitutional claims. It concludes that although kinship matching should not be implemented simply because it is technologically seductive, neither should it be removed from the realm of permissible law enforcement information gathering on constitutional grounds. In reaching this conclusion, the Article describes the logic of kinship analysis; clarifies the nature of partial-match searching; shows how an advanced system of DNA databases could yield additional, accurate leads in the investigation of both routine and high profile crimes; and why this system, if properly implemented, is compatible with constitutionally protected interests of both convicted offenders and their close relatives.Kaye comments that
DNA databases are a darling of the detective’s nursery. They began as a curiosity thought to be useful for solving only a few types of violent crimes. Today, they are a dazzling device for enforcing criminal laws from car theft to murder. Computerized matching of the DNA identification profiles from crime-scenes and victims to profiles from known individuals has produced hundreds of thousands of “cold hits.”
But some people are never satisfied. A number of scientists have concluded that the databases could produce many useful investigative leads if a technique known as kinship analysis were routinely employed. To take their idea to its logical extreme, we can envision a database system constructed to be especially useful for this kind of analysis. Like today’s databases, this system would pick out any individuals in the database who are likely sources of crime-scene DNA samples. But the trawling would not stop here. Almost magically, it could lead to identifications of individuals outside the database who left their DNA at crime scenes or on their victims.
Unfortunately, there is a catch. These new leads would point only to very close relatives who are not themselves subject to inclusion in the federal and state databases because they have not been convicted of crimes. Kinship matching therefore has been pilloried as “function creep,” “mission creep,” “a major privacy intrusion in the life of families,” “the worst kind of privacy intrusion,” “genetic surveillance for all,” and “lifelong genetic surveillance” that is “inconsistent with a basic pillar of American political thought.” And, as if all that were not enough, it has been tarred as “genetic determinism” and a step “towards eugenics and corruption of blood.”
Although early commentators perceived no fundamental legal barriers to kinship matching and most writing continues to focus on policy arguments, some recent commentary displays more sympathy or support for constitutional objections. The most prominent example is an essay by Professor Erin Murphy entitled Relative Doubt: Familial Searches of DNA Databases, which contends that the technique is a counterproductive police practice, unfair and unjust, and of doubtful constitutionality.
This Article provides a more complete examination of the two most significant constitutional issues—the Fourteenth Amendment’s guarantee of equal protection of the laws and the Fourth Amendment’s protection against unreasonable searches and seizures.
These constitutional provisions, I maintain, are not show-stoppers. Kinship matching should not be implemented simply because it is technologically seductive, but neither should be it be taken off the legislative table on constitutional grounds. To reach this conclusion, Part I describes the logic of kinship analysis and how it can be applied to state- of-the-art forms of DNA databases that could yield accurate leads in the investigation of both routine and high profile crimes. It introduces a few standard terms from genetics, presents more neutral terminology than the slightly ominous phrase, “familial searching,” and explains how kinship matching differs from the partial matching that the FBI allows in the national database (NDIS) that is part of the Combined Offender DNA Index System (CODIS). It also discusses the difficulty of measuring the efficacy of “familial searching.”
Parts II through IV analyze the two main constitutional objections to kinship matching. Part II argues that the practice is clearly compatible with the established understanding of the Equal Protection Clause. Parts III and IV analyze the interests of all convicted offenders and their families to show why kinship matching in law enforcement databases can qualify as a reasonable search or seizure under the Fourth Amendment. Like every other investigative technique, it can adversely affect very close relatives, but the actual Fourth Amendment interests of both the individuals in the database and their close relatives in keeping the state from finding investigative leads from crime-scene DNA are quite weak. The government interest in efficiently investigating crimes with a thorough and properly implemented system of kinship matching therefore outweighs these interests.