FAIRFIELD — A 22-year-old Fairfield city councilman was declared brain dead Tuesday as police searched for the person who shot him in the head outside a friend’s house.

An emotional Mayor Harry Price said at a news conference that the family of Councilman Matt Garcia had decided to take him off life support and “let him die naturally” at John Muir Medical Center in Walnut Creek, where he was taken with critical injuries after Monday night’s shooting.

Garcia had just stepped out of his car outside the friends home around 8:30 p.m. when someone fired several shots. A single bullet struck Garcia in the back of the head, Fairfield Police Chief Kenton Rainey said.

Authorities said they were trying to determine a motive in the shooting, whether Garcia was the intended target and if so, it had anything to do with his political position.

“We have no motive, no suspects,” Rainey said. “We are very, very early in our investigation.”

Gov. Arnold Schwarzenegger offered a $50,000 reward for information leading to the arrest and conviction of Garcia’s assailant.

One of the youngest elected officials in California, Garcia was just 21 when he was sworn in last fall as a councilman in this city of 105,000, the Solano County seat. He vowed to focus on crime prevention, economic development, community growth and keeping Travis Air Force Base in Fairfield, according to his campaign web site.

Garcia said his father had spent time in prison, used drugs and been involved with gangs, and he credited his grandmother and other family members from keeping him from a similar fate.

“I know what drugs and being a gang member can do to you...” he told Vacaville’s The Reporter newspaper last year. “I chose not to go that direction.”

Garcia was vice president of his senior class in high school, according to his campaign web site. He attended classes at Solano Community College in Fairfield after graduation and was working at a bank in Fairfield when he was elected to the council.

Fairfield officials opened up the City Council’s chambers Tuesday morning for colleagues, friends and supporters of Garcia’s seeking grief counseling.

Gary Falati, a former Fairfield mayor and mentor of Garcia’s, said he had plans to meet Garcia for coffee on Tuesday. Instead, Falati was anxiously waiting for updates on the young councilman’s condition.

“’It just makes me sick,” Falati told the Daily Republic newspaper in Fairfield.