(LOS ANGELES) -- More than 100 police officers were going door-to-door and searching for new tracks in the snow in the hopes of catching suspected cop killer Christopher Dorner overnight in Big Bear Lake, Calif., before he strikes again as laid out in his online manifesto.
Police held a news conference late Thursday, alerting the residents near Big Bear Lake that Dorner was still on the loose after finding his truck burning around 12:45 p.m. local time.
San Bernardino County Sheriff's spokeswoman Cindy Bachman said the authorities can't say for certain he's not in the area. More than half of the 400 homes in the area have been searched by police, who are traveling in two-man teams. Bachman urged people in the area to not answer the door, unless you know the person or it's law enforcement in uniform.
After discovering Dorner's burning truck near a Bear Mountain ski resort, police discovered tracks in the snow leading away from the vehicle. The truck has been taken to the San Bernardino County Sheriffs' crime lab.
Bachman would not comment on Dorner's motive for leaving the car or its contents, citing the ongoing investigation. Police are not aware of Dorner having any ties to others in the area.
She added that the search in the area would continue as long as the weather cooperates. However, a snowstorm was forecast for the area. About three choppers were being used overnight, but weather conditions were deteriorating, according to Bachman.
Dorner, a former Los Angeles police officer and Navy reservist, is suspected of killing one police officer and injuring another Thursday morning in Riverside, Calif. He was also accused of killing two civilians on Sunday. And he allegedly released an angry "manifesto" airing grievances against police and warning of coming violence toward cops.
In the manifesto Dorner published online, he threatened at least 12 people by name, along with their families.
"Your lack of ethics and conspiring to wrong a just individual are over. Suppressing the truth will leave to deadly consequences for you and your family," Dorner wrote in his manifesto.
One passage from the manifesto read, "I will bring unconventional and asymmetrical warfare to those in LAPD uniform whether on or off duty."
"I never had the opportunity to have a family of my own," it read. "I'm terminating yours."
Hours after the extensive manhunt dragged police to Big Bear Lake, CNN's Anderson Cooper said Dorner had sent him a package at his New York office that arrived on Feb. 1, though Cooper said he never knew about the package until Thursday. It contained a DVD of court testimony, with a Post-It note signed by Dorner claiming, "I never lied! Here is my vindication."
It also contained a keepsake coin bearing the name of former Los Angeles Police Chief William J. Bratton that came wrapped in duct tape, Cooper said. The duct tape bore the note, "Thanks, but no thanks Will Bratton."
Bratton told Cooper on his program, Anderson Cooper 360, that he believed he gave Dorner the coin as he was headed overseas for the Navy -- Bratton's practice when officers got deployed abroad. Though a picture has surfaced of Bratton, in uniform, and Dorner, in fatigues, shaking hands, Bratton told Cooper he didn't recall Dorner or the meeting.
Police say Dorner began his killing spree over the weekend, when a popular assistant women's college basketball coach, Monica Quan, and her fiancé, Keith Lawrence, were found dead in their car in Irvine, Calif., on Sunday.
Police identified Dorner as a suspect in the double murder late Wednesday night after discovering the online manifesto allegedly written by the suspect.
"Of particular interest at this point in the investigation is a multi-page manifesto in which the suspect has implicated himself in the slayings," Irvine police Chief David L. Maggard said at a news conference Wednesday.
Police claim Dorner bore a grudge against Quan's father, retired LAPD Capt. Randy Quan, for his firing from the department.
Dorner was with the department from 2005 until 2008, when he was fired for making false statements.
Randy Quan, 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.
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