IRVINE -- Police said Wednesday night they are looking for a former Los Angeles police officer suspected in the shootings of a Cal State Fullerton basketball coach and her fiancé, and they say the man is armed and dangerous.

Former LAPD officer and U.S. Navy reservist Christopher Dorner is a suspect in the killings of Monica Quan, 28, and Keith Lawrence, 27, who were found shot to death in their car at a parking structure Sunday night, Irvine police Chief David L. Maggard said at a news conference.

Maggard says Dorner, who was an LAPD officer until his dismissal in 2009, implicated himself in the killings with a multi-page manifesto he wrote that was obtained by police. Maggard gave no further details on the manifesto or its contents.

Police do not know Dorner's whereabouts, but his last address was in La Palma, and they are seeking the public's help in finding him, the chief said.

Dorner is expected to be armed and dangerous, and Maggard encouraged anyone who sees him to immediately call 911. Police said he may be driving a blue, 2005 Nissan Titan pickup truck.

The chief said the LAPD and FBI are assisting in the search.

Quan, an assistant women's basketball coach at Cal State Fullerton, is the daughter of a former LAPD captain, Randal Quan, who retired in 2002 and later worked as chief of police at Cal Poly, Pomona.

Lawrence, her fiancé, was a public safety officer at the University of Southern

Autopsies showed both were killed by multiple gunshot wounds in the parking structure at their condominium in Irvine.