Today’s decision will have far greater, practical impact on far more people than 95% of most Court decisions. (the marriage cases and Obamacare decisions being two of the 5%, but by contrast, the affirmative action decision coming soon will actually significantly impact far fewer people.) The opinions are models of clarity, by the way, and easily summarized by reference to their concluding paragraphs.
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 identi fication 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.
And that is that. If you arrested, the state gets your DNA, and can use it down the road.
From Justice Scalia’s dissent:
So the ironic result of the Court’s error is this: The only arrestees to whom the outcome here will ever make a difference are those who have been acquitted of the crime of arrest (so that their DNA could not have been taken upon conviction). In other words, this Act manages to burden uniquely the sole group for whom the Fourth Amendment’s protections ought to be most jealously guarded: people who are innocent of the State’s accusations.
Today’s judgment will, to be sure, have the beneficial effect of solving more crimes; then again, so would the taking of DNA samples from anyone who flies on an air- plane (surely the Transportation Security Administration needs to know the “identity” of the flying public), applies for a driver’s license, or attends a public school. Perhaps the construction of such a genetic panopticon is wise. But I doubt that the proud men who wrote the charter of our liberties would have been so eager to open their mouths for royal inspection.