An en banc panel of the 9th Circuit criticized a California law that allows police officers to collect DNA samples from anyone arrested for a felony.
Their comments contrast wildly with the opinion reached by a three-judge panel in February that allowed the statute to go forward.
"DNA is much more severe an intrusion than a fingerprint," said Judge Harry Pregerson, who seemed particularly disturbed by the law.
A class of sampling subjects sued the state in 2009, claiming the collection of DNA samples constituted an illegal seizure of their genetic information and violated their due-process rights. Lead plaintiff Elizabeth Haskell was arrested in March 2009 at a peace rally for allegedly obstructing an officer. She claims police told her she would be charged with a separate misdemeanor when she refused to let authorities swab the inside of her cheek, the typical method officers use to collect DNA.