Trawling Genealogy Databases and the Fourth Amendment: Part I

Law-enforcement use of a DNA database created for genealogy enthusiasts helped discover the man believed to be the Golden State Killer. It also provoked an immediate outpouring of media reports of concerns about "genetic privacy." Now, essays from groups of bioethicists and lawyers have appeared in both the Annals of Internal Medicine [1] and Science [2]. Neither article gives a convincing and complete analysis of the legal issues—hardly surprising given the word limits for such policy forum essays—but both are useful as starting points for discussion.

I. The Misplaced “Abandonment” Theory

The Annals article, Is It Ethical to Use Genealogy Data to Solve Crimes? [1], assures us that the law provides “clarity.” The authors find this clarity in “the abandonment doctrine.” The following paragraph comprises their entire legal analysis:

The legal questions raised by genealogy searches are measurably simpler than the ethical concerns. In terms of the U.S. Constitution, a genealogy search triggered by DNA collected from a crime scene probably would not count as a “search” under the Fourth Amendment (4). Even assuming it would, the applicable legal theory—the “abandonment doctrine”—holds that a person has no “reasonable expectation of privacy” in abandoned materials. Courts have allowed law enforcement to test DNA “abandoned” in a range of settings (such as hair clippings and discarded cigarette butts). At genealogy Web sites, users voluntarily upload (that is, abandon) familial data into commercial databases. Whether they are aware that their data are subject to police collection is, legally, irrelevant (5). Notwithstanding the clarity of the law, it is questionable whether it is good social policy to consider the uploading of genealogic data the same as abandoning DNA in a public space.

These remarks confuse two very different questions. The first is whether a data-gathering method is a search within the meaning of the Fourth Amendment. The Amendment protects against “unreasonable searches and seizures” of “persons, houses, papers, and effects,” in large part by requiring police to acquire judicial warrants based on probable cause before undertaking a search or seizure. (Reliance on a properly issued warrant makes the search reasonable.)

But not all information collection is a search or seizure that triggers the Fourth Amendment demand for reasonableness. For example, a police officer who merely watches a shady character—or anyone else—walk down the street has not searched or seized anyone. If the officer snaps a photo of the person and compares it to photos of wanted criminals, there is still no search or seizure, for there has been no interference with the individual’s body, movements, or property. And if no search has occurred, there is no need to ask whether the officer’s decision to study the individual was reasonable in light of the facts known to the officer. The notion that what a person knowingly exposes to the general public cannot be the subject of a “search” is sometimes called the “public exposure doctrine.” It pertains to the threshold question of whether a search has occurred.

The “abandonment doctrine” also applies to this threshold question. It applies to property that a person has discarded or left behind. If the police see an individual throw away a syringe, they may collect it and then analyze it for the presence of heroin without obtaining a warrant—because they have not performed a search that affects any legitimate interest. By intentionally relinquishing the syringe, the individual has given up any property interest. He or she might not want it to become known that the syringe has traces of heroin in it, but if heroin possession is a criminal act, then the individual can hardly claim that the interest in keeping this fact secret is legitimate and hence protected by the Fourth Amendment. So the abandonment doctrine is another route to a conclusion that the police have conducted no search or seizure within the meaning of the Amendment.

The lower courts have almost always applied the abandonment doctrine to DNA molecules shed or deposited in both legal and illegal activities. But it is odd to maintain, as Is It Ethical? does, that abandonment makes a search reasonable because “a person has no ‘reasonable expectation of privacy’ in abandoned materials.” That mistakes the question of whether a search is justified for the question of whether the police conduct is a search. The “reasonable expectation” standard, introduced in Katz v. United States, 389 U.S. 347 (1967), is merely a way to show that police have engaged in a search; it is not a way to show that a search is reasonable.

This distinction may sound finicky. Functionally, what is the difference between (1) defining everything as a search, but then asking whether the investigation is reasonable because there is no reasonable expectation of privacy in the items searched, and (2) asking whether there is a search because there is no reasonable expectation of privacy in the first place? The major difference is that the first inquiry focuses solely on the information-gathering practice's invasion of individual interests: Does the practice implicate an interest that the Amendment protects? The second question is broader and different. It asks how gravely the practice infringes that interest and how much the practice serves government interests that would be frustrated by the need to secure a warrant based on probable cause.

The use of the term "abandonment" to reject the claim that there has been a search does not automatically justify the search. The opinions allowing the police to profile shed DNA and compare the identifying profile with a suspect's DNA (or with all the profiles in a law enforcement DNA database), all without a warrant, do not demonstrate that police can also trawl a database of DNA sequences to see who might be related to whom. Further analysis is required to determine the constitutionality of familial, or other-directed searching by the state in both law-enforcement [3] and private (i.e., non-governmental) databases such as GEDmatch and the more restrictive commercial ones.

With respect to the private databases, the state's argument lies not so much in abandonment as in public exposure. The very reason the individual puts DNA data on the database is to enable curious members of the public to inspect it. As such, the Fourth Amendment issue is whether police (without a warrant) can do what anyone else can—namely, trawl the database for a partial match indicative of a genetic relationship to the suspect whose DNA is associated with a crime. In many contexts—overflying private property to get a look at what is there, for example—the Supreme Court has reasoned that what is open to the public generally is open to the police as well. Indeed, the Court has even held that entrusting or conveying information to private parties defeats the claim of a reasonable expectation of privacy and hence the claim of a search that requires probable cause and a warrant. Exposure to a small slice of the public—even a banker or a telephone company—is enough let the police in without a showing of probable cause. (Disclosure of information to one’s lawyer may be protected by the attorney-client privilege but not the Fourth Amendment.)

In the past several years, however, some Justices have evinced discomfort with this “third-party doctrine.” Just yesterday, the Court held in Carpenter v. United States, No. 16–402, 2018 WL 3073916 (U.S. June 22, 2018), that certain data generated by a cell-phone service provider—the third party—is not outside the protective umbrella of the Fourth Amendment just because it has been given to or generated by a third party. The data in the case amounted to extended tracking of the past whereabouts of a person’s cellphone’s via the electronic tracks, so to speak, left at cell towers. That information, the majority reasoned, was so sensitive as to make its possession by the cellular phone service providers insufficient to defeat the claim of a reasonable expectation of privacy. A warrant was required.

The Science article correctly frames the pivotal Fourth Amendment issue as the scope of the third-party doctrine, but it leaves much unsaid. I will turn to the implications of this evolving doctrine for trawls of genealogy databases in a later installment.

REFERENCES

1. Benjamin E. Berkman, Wynter K. Miller & Christine Grady, Is It Ethical to Use Genealogy Data to Solve Crimes?, Annals Internal Med., May 29, 2018, DOI: 10.7326/M18-1348.
2. Natalie Ram, Christi J. Guerrini & Amy L. McGuire, Genealogy Databases and the Future of Criminal Investigation, 360 Science 1078-1079 (2018) DOI: 10.1126/science.aau1083
3. David H. Kaye, The Genealogy Detectives: A Constitutional Analysis of “Familial Searching”, 51 Am. Crim. L. Rev. 109 (2013), https://ssrn.com/abstract=2043091

[Modified 29 Sept. 2018]