The US Supreme Court [official website] ruled [opinion, PDF] 5-4 Monday in Maryland v. King [SCOTUSblog backgrounder] that police may collect DNA samples from individuals arrested and charged with serious crimes. The respondent in the case, Alonzo King, challenged the validity of Maryland's DNA Collection Act [text, PDF] after state officials used his DNA to implicate him in a later crime. In an opinion by Justice Anthony Kennedy, the majority found that the warrantless DNA collection does not violate arrestees' Fourth Amendment [text] rights. Kennedy wrote:
In light of the context of a valid arrest supported by probable cause respondent’s expectations of privacy were not offended by the minor intrusion of a brief swab of his cheeks. By contrast, that same context of arrest gives rise to significant state interests in identifying respondent not only so that the proper name can be attached to his charges but also so that the criminal justice system can make informed decisions concerning pretrial custody. Upon these considerations the Court concludes that DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure. When officers make an arrest supported by probable cause to hold for a serious offense and they bring the suspect to the station to be detained in custody, taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment.The ruling reverses the decision of the Maryland Court of Appeals, which had been temporarily stayed [JURIST reports] by Chief Justice John Roberts last July.
Kennedy's majority opinion was joined by the chief justice and by Justices Clarence Thomas, Stephen Breyer and Samuel Alito. Justice Antonin Scalia filed a dissenting opinion, joined by Justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan. Scalia criticized the court's comparison of DNA collection to other techniques, such as fingerprinting: "The Court's assertion that DNA is being taken, not to solve crimes, but to identify those in the State's custody, taxes the credulity of the credulous. And the Court's comparison of Maryland's DNA searches to other techniques, such as fingerprinting, can seem apt only to those who know no more than today’s opinion has chosen to tell them about how those DNA searches actually work."