A former Los Angeles Police Department officer who is believed to be targeting officers and their families is wanted in connection with the ambush-style slaying Thursday morning of a Riverside officer and another shooting involving LAPD officers in Riverside County.

Law enforcement agencies across the state were on alert after three officers were shot -- two in Riverside, one in Corona -- Thursday morning. The shootings are likely connected to Christopher Dorner, a former LAPD officer wanted in a double slaying last weekend in Irvine who issued a manifesto regarding a revenge plot in response to his 2008 firing, according to police.

Timeline: Ex-LAPD Officer Murder Manhunt | Map: Manhunt Locations | Irvine PD: Christopher Dorner Alert | Read: Full Manifesto

The homicide Sunday in Irvine involved a former LAPD officer's daughter and her fiancé. During a Thursday morning news conference, LAPD Chief Charlie Beck characterized the rampage as a "vendetta against all of Southern California law enforcement" that prompted police security details for 40 "targets" mentioned in Dorner's manifesto.

Most of the subjects mentioned in the 11,400-word document are law enforcement officers and family members.

"Of course he knows what he’s doing," Beck said of Dorner, who likely has an arsenal of weapons, including a semi-automatic rifle. "We trained him."

The investigation into Dorner's location led deputies Thursday afternoon to the Big Bear area, where authorities found the man's burned pickup truck.

Nearby schools were placed on lockdown and Bear Mountain snow resort was closed for the day.

"He could be anywhere at this point," said San Bernardino County Sheriff John McMahon. "That's why we're searching door to door. We're doing everything we can to search the area in an attempt to find him."

Dorner's last known address is 4931 Sharon Drive in La Palma. He is described as 6 feet tall, about 270 pounds with black hair and brown eyes.

Rampage Began With Irvine Slayings

Dorner, 33, was identified as a suspect Wednesday in the slayings of Monica Quan, 28, and her fiancé, Keith Lawrence, 27, who were fatally shot Sunday while sitting in their car on the top level of a parking structure in the 2100 block of Scholarship Drive, according to Irvine police. The couple left a Super Bowl party at about 7 p.m. and were found slumped over in their car about 9 p.m.

Quan's father was the first Asian-American to become an LAPD captain, and also worked on the Asian Gang Task Force. In an online manifesto, Dorner repeatedly refers to a Randy Quan as being involved in his 2008 firing.

"The attacks will stop when the department states the truth about my innocence," Dorner writes in the manifesto.

Every officer mentioned in the document was provided with police protection, LAPD Sgt. Rudy Lopez said.

Dorner's identification as the suspect in the Irvine slayings and threats against law enforcement officers and their families prompted a "Blue Alert" -- a way to coordinate information about violent attacks on law enforcement officers.

Officers Shot, One Killed in Riverside County

The search led to Riverside County early Thursday after two LAPD officers -- part of a security detail assigned to one of the families mentioned in the Dorner manifesto -- encountered Dorner in Corona, Lopez said. The LAPD officers were flagged down by someone who recognized Dorner's vehicle at Magnolia Avenue near the 15 Freeway.

The gunman exited the vehicle and opened fire on officers with a "shoulder-type" weapon, said Lopez. One of the officers was shot, suffering what was described as a "minor" graze wound.

"It's extremely intense," Lopez said. "We're trying to identify where he's been, where he's going. In this case, we are the targets. He's brazen. He's on a hunt to do whatever havoc he can."

About 20 minutes later, two Riverside officers responded to Magnolia and Arlington avenues (map) after receiving a call for assistance. Both Riverside officers were shot and transported to a hospital, where one was pronounced dead.

"By all accounts, it appears they were stopped at a red light and just ambushed by the suspect," Riverside Lt. Guy Toussaint said. "The suspect did flee the scene, and we're in the process of trying to identify and apprehend the suspect at this time."

The second officer remained in surgery Thursday morning, but authorities said the officer's condition was stable.

The LAPD officers said it's likely Dorner is armed with a semi-automatic rifle.

"We're hoping to wake up and find out this is a bad dream," Riverside Police Chief Sergio Diaz said. "He has made it clear he considers police officers and their families fair game."

Dorner also is believed to be connected to an attempted boat theft in the San Diego area.

San Diego police were called to the Southwestern Yacht Club located at 2702 Qualtrough Street for an apparent boatjacking at 10:26 p.m. Wednesday.



An 81-year-old boat owner was on his 42-foot sundeck cruiser when a "heavy-set man in his 30s dressed in black clothing" robbed him, tied him up and pulled the boat out of the slip, officials said. The man could not start the boat so he took some items from the vessel and left, according to police.

Also early Thursday, the San Diego Harbor Police Department confirmed a badge along with Dorner's picture identification was found at about 2:27 a.m. in the center divider on Harbor Drive, near San Diego International Airport.

"Multi-Page Manifesto" Implicated Ex-LAPD Officer

LAPD officials said Wednesday that Dorner implicated himself in the Irvine couple's slaying in a "multi-page manifesto" that was published online but has since been taken down. A source inside LAPD gave NBC4 the manifesto, which is about 11,300 words long and appears to lay out a plan for targeting those involved in his firing.



In the manifesto -- addressed to "America" and titled "Last Resort" -- Dorner writes that the "horrendous murders" are "a necessary evil."



"I know I will be villified (sic) by the LAPD and the media," he writes. "Unfortunately, this is a necessary evil that I do not enjoy but must partake and complete for substantial change to occur within the LAPD and reclaim my name."



A one-time prep football player at Cypress High School before attending Southern Utah University in the late 1990s, Dorner goes on to say, "There will be an element of surprise where you work, live, eat, and sleep."

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