Los Angeles police said Saturday that they would reopen an investigation into the firing of Christopher Jordan Dorner, a former cop accused of killing three people as part of a revenge plot targeting law enforcement officers.

Dorner wrote a manifesto declaring war on police in retaliation for being fired from his job as an LAPD officer and losing an appeal to be reinstated. He promised to bring "unconventional and asymmetrical warfare" to officers and their families, calling it the "last resort" to clear his name and strike back at a department that he says mistreated him.

"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," Los Angeles Police Chief Charlie Beck said in a statement.

He said police would also look into any allegations made in the manifesto.

Beck addressed what he described as the "ghosts of the LAPD's past," and said that one of his biggest worries was that those ghosts would be "resurrected by Dorner's allegations of racism."

"As hard as it has been to change the culture of the Los Angeles Police Department, it has been even more difficult to win and maintain the support of the public. As much as I value our successes in reducing crime, I value even more our gains in public confidence," he said.

The development came as police continued their search for Dorner, 33, in snowbound mountains. Bundled up in winter gear, teams returned to the pine forests and trails surrounding Big Bear Lake in the San Bernardino Mountains.

As the dragnet entered its third day, questions continued Saturday about whether Dorner was still in the area, but police in California, Nevada and Arizona remained on alert.

Scouring the terrain by land and air, police were using helicopters, snowcats and armored personnel carriers with snow chains. The search resumed after overnight temperatures dipped into the teens.

Officers trudged through knee-high snow with rifles at the ready. Patrols again visited homes Saturday in Big Bear Lake, knocking on doors and peeking into windows. They had checked on the community's 400 homes Thursday.

"I don't think he is up here, to be quite honest with you, in this quite brutal weather," resident Justin Owen said. He was shoveling snow out of his driveway when a police team asked him if he had seen suspicious activity.

No, he told them.

Unlike his son, father Ed Owen believed Dorner could be hiding in any of the houses that serve as second residences in the mountains and are often vacant, frequently the case where families have owned the property for decades and lose interest in it, he said.

"I would guess the occupancy rate on my block is just 10%," Ed Owen told CNN. "If you really wanted to scout things out, you probably could find a home that is never occupied and hide in there."

Not far from the manhunt, skiers and snowboarders enjoyed an ideal day for winter recreation in the resort community.

"The possibility exists that he is here, somewhere in the forest, so we're going to keep looking ... until we determine that he's not here," said Cindy Bachman, a spokeswoman for the San Bernardino County Sheriff's Department.

Calamitous dragnet

Los Angeles police mistakenly shot and wounded two persons Thursday in Torrance as they drove a blue pickup truck resembling Dorner's vehicle. Torrance police also fired upon another blue pickup the same day, but no one was injured in that incident, a law enforcement source said.

The Los Angeles officers involved in the wounding of innocent civilians were put on paid administrative leave, police spokeswoman Rosario Herrera said Saturday. A day earlier, the LAPD had said the officers weren't put on such leave.

Unconfirmed sightings of the 270-pound, 6-foot Dorner have been reported as far away as Las Vegas and the California-Mexico border, according to reports.

LAPD spokesman Andrew Smith urged Dorner to turn himself in.

"That would be the best resolution for this whole thing right now," he said. "No one else has to be shot. No one else has to be injured. No one else has to die. He can turn himself in anywhere, and he'll be taken into custody, and he'll be able to get his side of the story out."

Dorner, who also served in the Navy, is suspected of killing two people in Irvine, California, on Sunday and shooting Thursday at three Los Angeles-area police officers, one of whom later died.

One of the victims of the Irvine killings, Monica Quan, was the daughter of the retired police officer who represented Dorner in his efforts to get his job back, police said.

According to a criminal complaint, someone claiming to be Dorner called the retired officer after the killing, telling him he "should have done a better job of protecting his daughter."