A third former Fullerton police officer has been charged in the beating death of a mentally ill homeless man after a violent confrontation with police last year, prosecutors said Thursday.

Former officer Joseph Wolfe was arraigned in Orange County on one felony count of involuntary manslaughter and one felony count of use of excessive force. He pleaded not guilty and surrendered on $25,000 bail, said Farrah Emami, a spokeswoman for the district attorney's office.

A grand jury indicted Wolfe, 37, on Monday, prosecutors said. He was released on bail, his attorney said, and is due back in court Nov. 2.

Wolfe was one of six officers involved in a violent clash with 37-year-old Kelly Thomas in July 2011 during an investigation into a report that Thomas was trying car doors at a Fullerton transit hub. Thomas died five days later.

The clash was captured on surveillance video and digital audio recorders worn by some of the officers. It stoked protests by residents, the recall of three councilmembers and an FBI investigation, in addition to criminal charges filed against two other officers last year. (MORE)