Familial Searches, the Fourth Amendment, and Genomic Control

In recent years, police have increasingly made use of consumer genomic databases to solve a variety of crimes, from long-cold serial killings to assaults. They do so frequently without judicial oversight per the Fourth Amendment’s warrant requirement by using consumer genomic platforms, which store hundreds of thousands or millions of user genomic profiles and enable law enforcement to infer the identity of distant genomic relatives who may be criminal suspects. This Essay puts this practice into context given recent legal and technological developments. As for the law, the Supreme Court in United States v. Carpenter has suggested that technologically driven and expansive datasets may be entitled to the full suite of Fourth Amendment protections. As for technology, we describe here the development of a novel technology that allows users to engage in genomic analysis in a secured environment without making such information available to a third party. Taken together, we present a possible technological solution to ensuring Fourth Amendment protections for direct-to-consumer genomic data.


Get a Warrant: A Bright-Line Rule for Digital Searches Under the Private-Search Doctrine – Note by Dylan Bonfigli

From Volume 90, Number 2 (January 2017)


A girlfriend hacks her boyfriend’s computer and discovers evidence of tax evasion. She contacts a local law enforcement officer who arrives at her house and looks at the files she found. Without a warrant, the officer opens other files in the same folder the girlfriend had searched. The officer notices another folder labeled “xxx.” He opens the folder and discovers child pornography. The officer seizes the computer based on what he found. The boyfriend is indicted for possession of child pornography and tax evasion. Before trial, the boyfriend moves to suppress all evidence obtained pursuant to the officer’s warrantless search of the computer. What evidence should the judge suppress?

The answer turns on the Fourth Amendment’s private-search exception. Under this exception, a government agent may recreate a search conducted by a private individual so long as the agent does not “exceed the scope” of the prior private search. The question under the existing framework is: at what point did the officer exceed the scope of the prior search—if at all? Was it when he viewed files the girlfriend had not viewed, when he opened files in a different folder, or did he stay within the scope of the girlfriend’s search by only searching the computer’s hard drive? This is what I will refer to as the denominator problem, which asks what courts should use as the unit of analysis to measure the scope of a digital search.

There are at least four competing approaches to the denominator problem, discussed in Part II, and the Supreme Court has provided little guidance on how the private-search doctrine applies to digital searches, resulting in a circuit split. Until this issue is resolved, law enforcement has little guidance on when to obtain a warrant following a private search and can unknowingly subject individuals to unreasonable invasions of privacy, which may result in suppression of relevant evidence. One recent example is United States v. Lichtenberger.