SAN FRANCISCO (CBS SF) — A 22-year-old San Francisco man who used a four-letter expletive during an encounter with police was found not guilty on Friday of five misdemeanor charges, including battery and resisting arrest, the public defender’s office said.

Chris Christopher had been sitting with a friend in a legally parked car at Newhall Street and La Salle Avenue in the Bayview District on April 9, 2010, when his mother saw the pair and pulled up alongside them in her car, the public defender’s office said.

An officer asked Christopher’s mother, who was parked illegally, for identification and then moved on to question Christopher, according to the public defender’s office.

The officer asked for Christopher’s name but didn’t believe him when he responded honestly, so Christopher fired back, “What if I tell you it’s, ‘F— you’?,” the public defender’s office said.

“It wasn’t respectful, but it was well within Mr. Christopher’s First Amendment rights,” his lawyer, Deputy Public Defender Erin Haney said in a statement. “There’s nothing in the penal code about having a smart mouth.”

An argument ensued in which Christopher allegedly threatened the officer, but witnesses who testified at the two-day trial denied that any threats took place, according to the public defender’s office.

The department said Christopher has a clean record.

At one point Christopher got out of the car, but he complied with police orders to return to it, the public defender’s office said. Soon after, officers allegedly pulled him out forcefully.

Christopher was arrested and charged with delaying or obstructing an officer with threat of violence, battery on a police officer, and three counts of resisting arrest, the public defender’s office said. The jury acquitted him on all charges.

Haney had argued in court that police had no right to detain Christopher and used excessive force.

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