A New York police officer was fighting for his life after being shot in the head on Sunday night on Staten Island, apparently by a 17-year-old parolee who was wanted for questioning on a new murder charge, the authorities said.

The officer, Gerard Carter, 28, was on a routine patrol of the West Brighton Houses project when he was shot at 9:25 p.m., Mayor Rudolph Giuliani said at a news conference at St. Vincent's Hospital on Staten Island. He was listed in critical condition and was undergoing brain surgery with his mother, ex-wife and girlfriend in close quarters.The suspect, Shatiek Johnson, was paroled in April after serving 11/2 years for a 1996 manslaughter conviction, the police said. He was arrested earlier this summer on a farebeating charge but somehow slipped through the parole system. He was most recently wanted for questioning in the July 16 shooting death of Eric Trotman, 20, on Staten Island, the police said.

Sunday night's incident was the most serious shooting of a New York City police officer since May, when a police officer was fatally shot in Brooklyn while trying to arrest a parolee.