The US Supreme Court has ruled that the police can take the DNA of anyone they arrest, just as they can take their fingerprints and photograph. Some justices sharply dissented in the 5-4 ruling, with conservative Antonin Scalia oddly joining three liberal justices in dissent.
Writing for the majority, Justice Anthony Kennedy wrote, "Taking and analyzing a cheek swab of the arrestee DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment." But Scalia, in a dissent read aloud in court, wrote, "Make no mistake about it: because of today's decision, your DNA can be taken and entered into a national database if you are ever arrested, rightly or wrongly, and for whatever reason."
Florida has already had a law of this nature for some time now.