A record $1m reward has been posted for information leading to the capture of a fugitive former Los Angeles policeman suspected of targeting fellow officers and their families in three killings committed in retaliation for his 2008 dismissal.
Los Angeles Police Department Chief Charlie Beck said on Sunday the reward, raised from private donations, police unions, businesses and city and county governments, is the largest sum ever offered in Southern California in a criminal investigation.
The reward was posted as law enforcement agencies across the region pressed on for a fourth day in their search for the suspect, ex-LAPD officer and US Navy reservist Christopher Dorner, 33.
Beck described it as the most extensive manhunt to ever be mounted in the Los Angeles area.
Police also were investigating a taunting phone call that may have been made by Dorner to the father of the woman they believe he killed last week.
Dorner has pledged revenge against several former Los Angeles Police Department colleagues whom he blames for ending his career.
On Saturday, Beck said officials would re-examine the allegations by Dorner, an African-American, that his law enforcement career was undone by racist colleagues.
While he promised to hear out Dorner if he surrenders, Beck stressed that he was ordering a review of his 2007 case because he takes the allegation of racism in his department seriously.
"I do this not to appease a murderer. I do it to reassure the public that their police department is transparent and fair in all the things we do," the chief said in a statement.
The search for Dorner has been focused in the snow-covered San Bernardino Mountains northeast of Los Angeles since a pickup truck belonging to Dorner was found abandoned and burning near the popular ski resort community of Big Bear Lake on Thursday.
The truck turned up hours after several alleged encounters with the suspect in the adjacent towns of Corona and Riverside east of Los Angeles.
There police said Dorner first exchanged gunfire with two officers, grazing one in the head. He later ambushed two more policemen in their patrol car at a stoplight, killing one and badly wounding the other.
A rambling, multi-page manifesto posted on Dorner's Facebook page last week claimed he was wrongly terminated from the LAPD in September 2008 and threatened to unleash "unconventional and asymmetrical warfare" on police officers and their families in revenge.
A former Navy lieutenant, Dorner also is suspected in last weekend's slayings of a campus security officer and his fiance, the daughter of a retired Los Angeles police captain singled out for blame in the manifesto for Dorner's dismissal.
The couple,Keith Lawrence, 27, and Monica Quan, 28, were found shot dead last Sunday in their car on the top level of a parking structure in the city of Irvine, south of Los Angeles.
Quan's father, Randy, had represented Dorner in disciplinary proceedings that led to his dismissal from the LAPD after a police inquiry found he had made false statements accusing a superior officer of using excessive force against a homeless person.
Dorner had ended his military service two days earlier, but the Navy has not disclosed the circumstances of his discharge.
In his online manifesto, Dorner said he would use "every bit of small arms training, demolition, ordnance and survival training I've been given" to bring "warfare'' to the LAPD and its families.
In the Navy, Dorner earned a rifle marksman ribbon and a pistol expert medal. He was assigned to a naval undersea warfare unit and various aviation training units, according to military records.
He took leave from the LAPD for a six-month deployment to Bahrain in 2006 and 2007.
The flight training that he received in the Navy prompted the Transportation Security administration to issue an alert, warning the general aviation community to be on the lookout for Dorner.
The extent of his potential flying skills was not known, the bulletin said.