Police launched a massive manhunt for a former Los Angeles officer suspected of killing a couple over the weekend and opening fire on four officers early Thursday, killing one and critically wounding another, authorities said.

The search for Christopher Dorner, who was fired from the Los Angeles Police Department in 2008 for making false statements, began after he was linked to the weekend killing in which one of the victims was the daughter of a former police captain who had represented him during those disciplinary proceedings.

Early Thursday, police came under fire in two separate shootings in Riverside County, east of Los Angeles.

The Riverside officers shot overnight were not actively looking for Dorner. The first occurred in Corona and involved two LAPD officers working a security detail, LAPD Sgt. Alex Baez. One officer was grazed. Later, two officers on routine patrol in neighboring Riverside were ambushed at a stop light, said Riverside Lt. Guy Toussaint. One died and the other was in surgery.

"We're asking our officers to be extraordinarily cautious just as we're asking the public to be extraordinarily cautious with this guy. He's already demonstrated he has a propensity for shooting innocent people. We can't provide a lot of information now because we're trying to capture him," said Cmdr. Andrew Smith. "We don't know where he is. We're looking for the public's help to locate this guy. Anybody who sees him or believes they see him or his vehicle should call 911."

Dorner's LAPD badge and an ID were found near San Diego's airport and were turned in to police at early Thursday, San Diego police Sgt. Ray Battrick said.

Dorner is wanted in the killings of Monica Quan and her fiance, Keith Lawrence, 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 Wednesday night.

Read it at The Huffington Post.