When Is It OK to Take People's DNA Without Their Consent?

From The Atlantic:

If you're walking down the street and a police officer wants to swab your cheek for a DNA sample, you can refuse. But if you're convicted of a felony, you can't. At what point in the criminal process do you lose that right?

In California, until last week, the answer was the moment you were arrested for a felony. But a California state court has struck down the state statute that allowed such DNA collection, saying the measure 'unreasonably intrudes on such arrestees' expectation of privacy and is invalid under the Fourth Amendment of the United States Constitution.'

The decision comes at a crucial time in the legal battle over DNA evidence: Last summer, a three-judge panel on the federal Ninth Circuit heard arguments about California's law and has yet to issue its opinion. This fall, the circuit will sit en banc -- that means all of the judges not just three of them -- to decide whether a very similar federal law is constitutional. Another circuit court has already decided that it is. If the two circuits disagree (or even if they don't), the issue could come before the Supreme Court soon.