Irvine police on Wednesday night named Christopher Dorner as the suspect in the case, saying he was armed and dangerous. He was driving a blue 2005 Nissan Titan pickup with a license plate 7X03191. He lived in La Palma, Calif.
Dorner was fired by the Los Angeles Police Department several years ago for allegedly making false statements about his training officer.
Details of the manifesto were not immediately available. But sources said that in the writings he threatens LAPD officers and commanders — including those who were on the review board that ultimately fired him.
The victims were found shot to death in the parking garage of their Irvine condominium complex Sunday night. The Orange County coroner said each died of multiple gunshot wounds.
Autopsies have been completed for Monica Quan, 28, an assistant women's basketball coach at Cal State Fullerton, and Keith Lawrence, 27, a public safety officer at USC, said Jim Amormino, a spokesman with the Orange County Sheriff's Department.
He would not elaborate on the cause of death, or give information about how many times the engaged couple had been shot and where on the bodies the wounds were, citing the ongoing investigation.
Authorities are still searching for leads in the crime, which police do not believe was a murder-suicide, or motivated by robbery.
Investigators have said little about the crime or other possible suspects.
The two were engaged in January and had recently moved into an upscale condominium complex near UC Irvine and Concordia University, where both were basketball stars, family members said.