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Criminal Procedure

License, Registration, Cheek Swab: DNA Testing and the Divided Court

Midway through the oral argument in Maryland v. King, Justice Alito spontaneously interjected: “[B]y the way, I think this is perhaps the most important criminal procedure case that this Court has heard in decades.” The juxtaposition between the breeziness of his comment and the solemnity of its content befit the case, which is best characterized as a sleeper in a Term overshadowed by monumental rulings on gay marriage, voting rights, and affirmative action. What looked on its face like just another Fourth Amendment dispute – with civil libertarians on one side and law enforcement on the other – garnered no special attention. But King is no ordinary Fourth Amendment case.

At first glance, King simply upheld the Fourth Amendment constitutionality of a state statute authorizing the collection of DNA from arrestees. But the opinion in the case represents a watershed moment in the evolution of Fourth Amendment doctrine and an important signal for the future of biotechnologies and policing. This Comment places King into context from three different vantage points, each one step removed. Specifically, the three Parts below address the significance of the opinion: for DNA collection from arrestees, for forensic DNA practices more generally, and for the Fourth Amendment.

Part I briefly summarizes the opinions in the case and may be skipped by those familiar with them. Part II reads between the lines of the majority opinion, in light of the greater constellation of facts and claims placed before the Court, to underscore the significance of what was not said about the constitutionality of arrestee DNA collection. Part III considers King as it exemplifies the judicial response to forensic DNA typing more generally, and imagines its precedential value in future biometric cases. Part IV situates King in the broader landscape of the Court’s recent Fourth Amendment jurisprudence and analyzes its insights for the evolution of the field as a whole.