UPDATE 2:34 p.m. Breaking news, profiles, timeline, reaction, photos: For all KPCC coverage of the manhunt click HERE.

UPDATE 10:20 a.m.: LAPD Police Chief Charlie Beck says a massive manhunt is underway for a former police officer that is a suspect in the shooting of four police officers, killing one Riverside police officer. Christopher Dorner is also a suspect in the double homicide of a couple in Irvine and the woman was the daughter of an attorney who represented him at a LAPD disciplinary matter.

The first shooting early Thursday morning occurred in Corona when two LAPD police officers on their way to protect someone whose life Dorner threatened were fired upon near the exit of Magnolia Avenue off of Interstate 15. The LAPD officers returned fire. One of them was grazed in the head and survived.

Chief Beck did not say if they believe Dorner was hit.

The LAPD patrol car was damaged and the offcers could not give chase.

Minutes later, two Riverside police officers were "ambushed" while at a red light. One of the officers died; the second was taken to the hospital and underwent surgery. Their identities have been released.

At about 5:15 a.m., LAPD officers protecting a person threatened by Dorner fired upon a truck that matched the description of one driven by the suspect. The truck was driving down the street with its lights off, the chief said.

Two people were hit and are expected to survive.

“It was one of the people under most serious level of threat,” Beck said, about the person who was under LAPD protection. "We believe this was a case of mistaken identity by the officers.”

RELATED: Timeline: The search for Christopher Dorner

Images from Dorner's Facebook page and scenes of shootings

LAPD manhunt: Twitter tracks search for Christopher Dorner

Beck said officers in the region are on alert because Dorner is highly trained in weapons and police tactics from his time in the Navy and at LAPD.

“Of course he knows what he’s doing. We trained him,” Beck said during a news conference at LAPD headquarters Thursday morning. "I would tell him to turn himself in. This has gone far enough.”

Dorner may have also been down in San Diego. On Wednesday night, a man matching Dorner's description tries to steal a 47-foot boat from a San Diego marina but the engine won't start. An 81-year-old man on the boat is tied up but not hurt.

Police say they found some of Dorner's belongings in a trash bin in the San Diego-area community of National City, Calif. on Monday. Then, about 2:30 a.m. Thursday, a passer-by finds a wallet with law enforcement badge and a picture ID of Dorner on a street near San Diego International Airport.

We will update this story as more information becomes available.

PREVIOUSLY: Los Angeles police say officers guarding a target in an ex-officer's manifesto shot and wounded multiple people in Torrance who were in a pickup.

LAPD Lt. Andrew Neiman says the officers were deployed in response to Christopher Dorner's written threats to department officials in a rambling 14-page manifesto.

Authorities say Dorner has implicated himself in the killing of two people in Irvine over the weekend. He's also the suspect in the overnight killing of a police officer and critical wounding of another cop.

Police did not say how seriously the people in Torrance were injured.

We will provide further details as they become available.

PREVIOUSLY: Police continue 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. 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. The Riverside officers shot overnight were not actively looking for Dorner, Toussaint said. "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 early Thursday, San Diego police Sgt. Ray Battrick said. The Los Angeles Times reports that earlier this week he tried to steal a boat in San Diego and flee to Mexico. 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. Dorner, 33, implicated himself in the killings with a multi-page "manifesto" that he wrote that included threats against several people, including members of the LAPD, police said. They gave no further details on the document or its contents. Venice 311 posted what it said was the manifesto; the veracity of the site's posting could not be independently verified. Autopsies showed that Quan and Lawrence were killed by multiple gunshot wounds in the parking structure at their condominium in Irvine, Orange County sheriff's spokesman Jim Amormino said earlier Wednesday. Quan, 28, was an assistant women's basketball coach at Cal State Fullerton. Lawrence, 27, was a public safety officer at the University of Southern California. The killings brought mourning and disbelief at three college campuses, Fullerton, USC, and Concordia University, where the two met when they were both students and basketball players. Police said the U.S. Navy reservist may be driving a blue 2005 Nissan Titan pickup truck. His last known address was in La Palma in northern Orange County near Fullerton. Dorner was with the department from 2005 until 2008, when he was fired for making false statements. Quan's father, a former LAPD captain who became a lawyer in retirement, represented Dorner in front of the Board of Rights, a tribunal that ruled against Dorner at the time of his dismissal, LAPD Capt. William Hayes told The Associated Press Wednesday night. Randal Quan retired in 2002. He later served as chief of police at Cal Poly Pomona before he started practicing law. According to documents from a court of appeals hearing in October 2011, Dorner was fired from the LAPD after he made a complaint against his field training officer, Sgt. Teresa Evans. Dorner said that in the course of an arrest, Evans kicked suspect Christopher Gettler, a schizophrenic with severe dementia. Following an investigation, Dorner was fired for making false statements. Richard Gettler, the schizophrenic man's father, gave testimony that supported Dorner's claim. After his son was returned on July 28, 2007, Richard Gettler asked "if he had been in a fight because his face was puffy" and his son responded that he was kicked twice in the chest by a police officer. We will provide further details as they become available.

PREVIOUSLY: A badge found in San Diego County has been linked to cop shooting suspsect Christopher Jordan Dorner.

San Diego police said a passerby found the badge about 2:20 a.m. on Harbor Drive near Lindbergh Field and turned it over to police, according to the UT-San Diego newspaper. Police said the badge had identification in it that indicated it belonged to Dorner.

PREVIOUSLY: The LAPD officer shot in Corona was enroute to offer protection to a person who may have been a target of ex-Los Angeles police officer Christopher Jordan Dorner, who is a suspect in the shooting of two other officers, including one fatally, and is wanted for the slayings of a couple in Irvine.

LAPD Sgt. Rudy Lopez says the officers were in a patrol vehicle and in uniform when there were shot at by Dorner. One officer was grazed and treated for the wound.

Dorner has made specific threats to current and former LAPD personnel.

“It’s hard to fathom why he’s doing what he’s doing and get in his mindset," Lopez said. "But based on what he’s wearing, his actions out here, the type of weaponry that he’s using – he’s out for war.”

He is also suspected of shooting at two Riverside police officers who happened to be near the area of the shooting in Corona. One of those officers died in what was described as an "ambush." The other officer is in surgery.

This story will be updated throughout the day.

PREVIOUSLY: A former Los Angeles police officer sought for two weekend killings – and who threatened to kill police – is a suspect in an overnight shooting in nearby Riverside County that killed one officer and critically wounded another, police said Thursday.

The shooting happened early Thursday morning in the Los Angeles suburb of Corona. The wounded officer is in surgery. A third officer suffered a graze wound.



Two Newton station officers on security duty in the same area were also involved in a shooting overnight, but they weren't hurt, police said.



Former Los Angeles police officer Christopher Jordan Dorner is the suspect who is wanted in the killings of Monica Quan and her fiancé, 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.



Dorner, 33, implicated himself in the killings with a multi-page "manifesto" that he wrote that included threats against several people, including members of the LAPD, police said. They gave no further details on the document or its contents.

The California Highway Patrol issued an alert: "The suspect (Dorner) is armed and extremely dangerous (and) a blue alert has been activated in Los Angeles, Ventura, Riverside, Orange, San Bernardino, San Diego, Imperial, Kern, and Santa Barbara counties."

Police presence was heavy along Southern California freeways and roads Thursday morning.

The CHP said at about 1:22 a.m. Dorner was involved in multiple shootings with multiple police agenices in the Riverside area.



Autopsies showed that Quan and Lawrence were killed by multiple gunshot wounds in the parking structure at their condominium in Irvine, Orange County sheriff's spokesman Jim Amormino said earlier Wednesday.



Quan, 28, was an assistant women's basketball coach at Cal State Fullerton. Lawrence, 27, was a public safety officer at the University of Southern California.



The killings brought mourning and disbelief at three college campuses, Fullerton, USC, and Concordia University, where the two met when they were both students and basketball players.



Police do not know Dorner's whereabouts, and authorities were seeking the public's help in finding him.



"We have strong cause to believe Dorner is armed and dangerous," Maggard said, adding that the LAPD and FBI are assisting in the case.



Police said the U.S. Navy reservist may be driving a blue 2005 Nissan Titan pickup truck. His last known address was in La Palma in northern Orange County near Fullerton.



Dorner was with the department from 2005 until 2008, when he was fired for making false statements.



Quan's father, a former LAPD captain who became a lawyer in retirement, represented Dorner in front of the Board of Rights, a tribunal that ruled against Dorner at the time of his dismissal, LAPD Capt. William Hayes told The Associated Press Wednesday night.



Randal Quan retired in 2002. He later served as chief of police at Cal Poly Pomona before he started practicing law.



According to documents from a court of appeals hearing in October 2011, Dorner was fired from the LAPD after he made a complaint against his field training officer, Sgt. Teresa Evans. Dorner said that in the course of an arrest, Evans kicked suspect Christopher Gettler, a schizophrenic with severe dementia.



Following an investigation, Dorner was fired for making false statements.



Richard Gettler, the schizophrenic man's father, gave testimony that supported Dorner's claim. After his son was returned on July 28, 2007, Richard Gettler asked "if he had been in a fight because his face was puffy" and his son responded that he was kicked twice in the chest by a police officer.

PREVIOUSLY: Three law enforcement officers were shot early Thursday morning – one in Corona and two in Riverside – by a gunman believed to be Christopher Jordan Dorner, the fired Los Angeles Police Department officer wanted for the slayings of a college basketball coach and her fiancé in Irvine, police said.

A tweet from the official Twitter account of the Riverside Police Department says that at least one of the Riverside police officers shot in that city has died:

"RPD officer murdered. Magnolia and Arlington closed at intersection until further notice."

The other officer shot in Riverside is in surgery, according to Riverside police Lieutenant Guy Toussaint. The shooting occurred at about 1:35 a.m. Thursday.

Toussaint did not provide any further details, including suspect information.

However, the California Highway Patrol has issued an alert to law enforcement around the state that Dorner is a suspect in the shootings in Riverside County:

*THE SUSPECT IS CONSIDERED ARMED AND EXTREMELY DANGEROUS* A BLUE ALERT HAS BEEN ACTIVATED IN THE FOLLOWING COUNTIES: KERN, SANTA BARBARA, VENTURA, LOS ANGELES, SAN BERNARDINO, ORANGE, RIVERSIDE, SAN DIEGO, AND IMPERIAL. ON FEBRUARY 7, 2013, AT APPROXIMATELY 0122 HOURS, THE SUSPECT WAS INVOLVED IN MULTIPLE SHOOTINGS WITH MULTIPLE AGENCIES IN THE RIVERSIDE CHP AREA.



THE SUSPECT IS CHRISTOPHER JORDAN DORNER, A 33 YEAR OLD, BLACK, MALE, 6 FEET TALL, 270 POUNDS, WITH BLACK HAIR, BROWN EYES, WITH AN UNKNOWN CLOTHING DESCRIPTION. THE SUSPECT WAS LAST SEEN DRIVING A 2005 BLUE OR GRAY NISSAN TITAN, WITH A CA LICENSE PLATE OF 8D83987 or 7X09131 - THE SUSPECT MAY BE SWTICHING BETWEEN THE TWO LICENSE PLATES.

THE VEHICLE ALSO HAS SKI RACKS ON IT'S ROOF. IF SEEN CONTACT RIVERSIDE POLICE DEPARTMENT AT (951) 787-7911.

There are two perimeters set up in Riverside County as detectives investigate the shootings. One of them is affecting traffic on Interstate 15: The Magnolia Avenue exit is closed and there are many law enforcement officers gathered there. A SigAlert has been issued.

That is where an officer from the Los Angeles Police Department was shot at and suffered a graze wound. There are numerous officers staged on the freeway overpass at that location.

We will update this story throughout the day.

Authorities on Wednesday night said they were seeking Dorner as a suspect in the killings of two people, including a Cal State Fullerton basketball coach whose father represented Dorner in front of a disciplinary board when he lost his job.

Monica Quan, 28, and her 27-year-old fiancé 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.

Police said Dorner implicated himself in the killings with a multi-page "manifesto" that he wrote that included threats against several people, but would give no further details on the document or its contents.

Dorner was with the department from 2002 until 2009, when he was fired for making false statements.

Quan's father, Randal Quan, a former LAPD captain who became a lawyer in retirement, represented Donner in front of the Board of Rights, a tribunal that ruled against Donner at the time of his dismissal, LAPD Capt. William Hayes told The Associated Press Wednesday night.

Randal Quan, who the LAPD said was the first Chinese-American captain in department history, retired in 2002. He later served as chief of police at Cal Poly Pomona and went on to practice law.

Police said Dorner's manifesto included threats against members of the LAPD.

"We are looking at the manifesto and will do an assessment in terms of the threat against those listed in it, and determine what level of protection each of them will need," Hayes said.

Soon after Dorner was identified as the suspect in the killings, messages appeared on Twitter that linked to what may be the “manifesto” the Irvine Police said had led them to conclude that the ex-LAPD officer was the killer.



The Facebook message includes threats against LAPD personnel whom Dorner apparently encountered in the course of the department's disciplinary proceedings against him. It describes them as “high value targets” and goes on to promise “operations to destroy, exploit and seize designated targets.”



The targets include murder victim Michelle Quan's father, Randal Quan.



It also demands that the LAPD clear Dorner's name, saying in stark terms: “The attacks will stop when the department states the truth about my innocence, PUBLICLY!!!”



The LAPD issued a statement (embedded below) confirming that threats had been made against its officers.

Venice 311 posted what it said was the manifesto; the veracity of the site's posting could not be independently verified.

Police are searching for Dorner, described as being 6 feet tall, about 270 pounds with black hair and brown eyes. He may be driving a blue, 2005 Nissan Titan pickup truck (Calif. license plate 7XO3191), and his last known address was in La Palma, Calif.

Dorner was an LAPD officer until his dismissal in 2009.

According to documents from a court of appeals hearing in October 2011, Dorner was fired from the LAPD after he made a complaint against his field training officer, Sgt. Teresa Evans, saying in the course of an arrest she kicked suspect Christopher Gettler, a schizophrenic with severe dementia.

Following an investigation, Dorner was fired for making false statements.

Richard Gettler, the schizophrenic man's father, gave testimony that supported Dorner's claim. After his son returned on July 28, 2007, Richard Gettler asked "if he had been in a fight because his face was puffy" and his son responded that he was kicked twice in the chest by a police officer, he testified.

The chief took no questions during the brief news conference.

Autopsies showed the couple found dead in Irvine Sunday night were killed by multiple gunshot wounds in the parking structure at their condominium, Orange County sheriff's spokesman Jim Amormino said earlier Wednesday.

The killings brought mourning and disbelief at three college campuses, Fullerton, USC, and Concordia University, where the two met when they were student athletes.

Dorner LAPD Statement Regarding Christopher Jordan Dorner by