A federal appeals court reinstated a damage suit against San Francisco police Monday by a driver who was held at gunpoint, on her knees, because a police camera misidentified her car as a stolen vehicle, and officers failed to look at her license plates before pulling her over.

Denise Green, who works for the city as a Muni driver, sued for wrongful detention and excessive force after the March 2009 incident. U.S. District Judge Richard Seeborg dismissed her suit, saying police had made a good-faith, reasonable mistake in treating her as a car thief, but the Ninth U.S. Circuit Court of Appeals said a jury should decide whether the officers had gone too far.

"A rational jury could find that (the officers and the city) violated Green's Fourth Amendment rights" against unreasonable search and seizure, the court said in a 3-0 ruling.

Green, 47, a San Francisco resident with no criminal record, was driving her 1992 Lexus on Mission Street late one night when the automatic license-plate scanner on a police cruiser identified her car as stolen. The stolen vehicle was actually a truck with a one-digit difference in the license plate, the court said.

Officer Alberto Esparza, who was driving the cruiser, couldn't see Green's plate or read the blurry photo, so he radioed a dispatch office that verified that the number picked up by the scanner came from a stolen vehicle. Sgt. Ja Han Kim, patrolling nearby, heard the message, spotted Green's car and, without reading her license plate, called for backup support and pulled her over.

Between four and six officers ordered Green out of the car, treating her as a high-risk suspect. While other officers pointed their guns at her, Kim ordered her to get on her knees and handcuffed her. The police patted her down, searched the car and ran a check of her actual license plate number, which revealed their mistake. They removed the handcuffs but held her while they finished their paperwork. Green said she was in cuffs for as long as 10 minutes.

Because the license-plate scanner was known to make occasional errors, the court said, it was common police practice - but not a formal policy - to visually confirm the plate numbers before relying on the scanner's information.

That practice wasn't followed in this case, the court said, and a jury could conclude that Kim acted unreasonably in pulling Green over. Jurors could also find that Green posed no threat to the officers and that they used excessive force by ordering her to her knees and training their guns on her, the court said.

That part of the ruling should lead to a change in San Francisco police practices, said Green's lawyer, Michael Haddad. "They have been automatically pointing guns anytime they believe a car was stolen," he said.

Gabriel Zitrin, spokesman for City Attorney Dennis Herrera, said the office was disappointed by the ruling but was prepared to take the case to trial.