SAN DIEGO - A U.S. Marshals Service official says the search for Dorner has spread from California to Nevada, Arizona and Mexico.
Police in San Diego say they are responding to a possible local sighting of Christopher Dorner, the suspect in the shootings of three officers, as well as the slaying of a college basketball coach and her fiancé in Irvine.
Watch Live: Coverage of search for Dorner
According to San Diego Police Department officers, someone reported seeing Dorner on Harbor Drive and Landing Road, near the U.S. Navy Fleet Anti-Submarine Warfare Training Center in Point Loma.
Police in San Diego say they found the identification of Dorner early Thursday morning.
Officers said a wallet containing a badge and Dorner's identification was found near Lindbergh Field. The items were found along Harbor Drive by a passerby and turned over to police around 2:20 a.m., according to San Diego police Officer Frank Cali. It was not immediately clear what agency the badge represented or whether it was legitimate but the identification was clearly for Dorner, he said.
In addition, National City police told 10News that they found property believed to belong to Dorner, the fired Los Angeles Police Department Officer wanted for the revenge slayings in Irvine.
Police have issued a Blue Alert -- specifically sent out when there is a threat to officer safety -- for multiple counties in the manhunt for Dorner.
At a news conference, LAPD officials confirmed that Dorner unsuccessfully tried to steal a yacht from the Southwestern Yacht Club in Point Loma. The attempted boat jacking occurred Wednesday at about 10:30 p.m.
According to the L.A. Times, a gunman told the 81-year-old boat owner to take him to Mexico. The suspect later tied up the owner and tried to take the 47-foot vessel. The suspect, however, was not able to operate the boat. The suspect in the attempted boat jacking was described as a heavy set man in his 30s dressed in black clothing.
1 officer from Riverside killed in shootings
A Riverside police officer was shot to death Thursday and one was wounded by a gunman believed to be Dorner. The gunman, who fled after the shooting in Riverside, ambushed the two officers while they were stopped at a red light, said Riverside police Lt. Guy Toussaint, adding that the two were on patrol and not searching for Dorner.
The wounded Riverside officer was undergoing surgery Thursday morning, Toussaint said.
Before the Riverside shooting, a shooting in Corona also believed to have involved Dorner left a Los Angeles police officer with a graze wound, but his partner was not hurt, police said. The two officers are assigned to the Los Angeles Police Department's Newton Station, said Newton Station Sgt. Ike Ornelas.
Dorner, a U.S. Navy reservist whose last known address was in the 4900 block of Sharon Drive in La Palma.
Dorner is 6 feet tall and weighs 270 pounds, and he was last seen in a gray Nissan Titan with the license plate 8D83987. But, police say they believe he may be switching between license plates and he was also seen in a vehicle with the plate 7X03191.
Dorner was being sought by Irvine police, Los Angeles police, the FBI and U.S. Marshals Service. He may be anywhere between Los Angeles and San Diego, Maggard said.
Anyone encountering Dorner should consider him "armed and extremely dangerous" and should not approach or try contacting him but instead call 911 immediately, according to the LAPD.
A tip line has been established, (949) 724-7192.
10News learned that LAPD officers will not be on motorcycles Thursday and will be in groups of two. LAPD will continue to give updates throughout the day.
Los Angeles police say officers guarding a person believed to be targeted by Dorner, shot and wounded multiple people in Torrance who were in a pickup.
LA police says the officers were deployed in response to Dorner's written threats to department officials in a rambling 14-page online manifesto.
Police did not say how seriously the people in Torrance were injured.
2 found dead in Irvine garage
Dorner was represented in the hearing that resulted in his firing by Randy Quan, the father of Monica Quan, slain with Keith Lawrence on Sunday, Irvine Police Department Chief David Maggard said Wednesday.
Dorner posted a multi-page manifesto online Monday, saying he didn't mind dying, because he died when he was fired from the LAPD, Maggard said.
Dorner blamed Randy Quan, a retired Los Angeles Police Department officer, for his firing.
"I never had the opportunity to have a family of my own ... (so) I am terminating yours," Dorner wrote to Randy Quan.
The LAPD's elite Metropolitan squad was sent to protect others mentioned in Dorner's manifesto.
The LAPD issued a statement Wednesday declaring that it was taking the threats
"very seriously," implementing "all measures possible to ensure the safety of our LAPD personnel, their families and the Los Angeles community, and will continue to do so until Dorner is apprehended and all threats have been abated."
Dorner worked as a police officer from Feb. 7, 2005 until Sept. 4, 2008, "when his employment was terminated," police said.
Police who received a call at 9:10 p.m. Sunday about a person slumped over in a parked car at 2100 Scholarship found the recently engaged couple dead in Lawrence's Kia, which was parked at the top of the five-story structure for the building where they lived.
There was no evidence Lawrence and 28-year-old Monica Quan were being robbed, said Irvine police Lt. Julia Engen, who noted that the high-density residential community is highly secure with key card access only.
Irvine had two slayings in both 2011 and 2012, according to Engen, who said overall violent crime is at "historic lows" in the city.
Monica Quan was in her second season as an assistant coach for the Cal State Fullerton women's basketball team after holding a similar position at California Lutheran University in Thousand Oaks.
The couple met while at Concordia University in Irvine, where they both played basketball. Lawrence was seeking a career in law enforcement, which made him a good match for Monica Quan because her father was an LAPD officer, friends said.
The 27-year-old Lawrence, who graduated from the Ventura County Sheriff's Academy, was working as a patrol officer at USC's Department of Public Safety. He joined the department in August, said Carl Marziali, USC's assistant vice president of media relations.
Monica Quan was a star athlete at Walnut High School, then played at Cal State Long Beach from 2003-05 before transferring to Concordia University, where she graduated in 2007 with a degree in exercise and sports science. She received a master's degree from Concordia in 2009.
Autopsies on the bodies of Lawrence and Monica Quan were completed Tuesday and Wednesday, respectively, said Jim Amormino of the Orange County Sheriff's Department.
"The coroner determined that both died of multiple gunshot wounds," Amormino said. "No further information will be released at this time."