BIG BEAR LAKE, California (CNN) -- Police resumed their manhunt in snowbound mountains Saturday for an ex-Los Angeles cop accused of killing three people as part of a revenge plot targeting law enforcement officers.
Bundled up in winter gear, teams returned to the pine forests and trails surrounding Big Bear Lake in the San Bernardino Mountains in a search for Christopher Jordan Dorner, 33, who also served in the Navy.
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.
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.
Police have searched an undeveloped tract owned by Dorner's mother in Arrowbear Lake, about 13 miles from Big Bear Lake, but police found nothing, Bachman said. The property doesn't have a house on it, she said.
The manhunt in Southern California hasn't been without calamity.
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 department 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.
Dorner, 33, wrote a manifesto declaring war on police and their families in retaliation for being fired from his job as an LAPD officer and losing an appeal to be reinstated.
Dorner 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.
Los Angeles Mayor Antonio Villaraigosa described Dorner as "a very sick individuaI."
"There is absolutely nothing that was done to this individual that would rationalize in any way the murder of three innocent people," Villaraigosa told CNN on Saturday. "The notion that somehow this deranged individual be given any credence boggles my mind."
For now, the focus of the manhunt remains on Big Bear and the surrounding mountains, where Dorner's burned-out pickup was found Thursday.
The truck had a broken axle, which would have prevented the truck from moving, and footprints appear to show Dorner doubled back into the community, according to a source with knowledge of the investigation.
It was unclear where Dorner may have gone from there or by what means, the source said.
Guns found in the truck also were burned, but authorities believe Dorner may have as many as 30 weapons with him, said the source, who spoke on condition of anonymity. The source was not authorized to release details to the media.
Dorner, who retired from the Navy Reserve on February 1 as a lieutenant, was trained in counterinsurgency and intelligence, the source said.
Dorner promised to bring "unconventional and asymmetrical warfare" to police officers and their families, calling it the "last resort" to clear his name and retaliate at a department that he says mistreated him.
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.
Two inches of snow Friday coated the mountaintop pine trees and roads around Big Bear Lake, a popular skiing area two hours east of Los Angeles, leading motorists to use tire chains. Up to six more inches were expected.
Big Bear Lake Mayor Jay Obernolte said residents were not fearful and that "many of the people here are armed."
"Is there panic in our community? No, there is no panic. We're a hearty people in the San Bernardino Mountains," he said.
San Bernardino County Sheriff John McMahon said the snowfall
"The snow is great for tracking folks, as well as looking at each individual cabin to see if there's any sign of forced entry," he said.
Meanwhile Navy installations throughout California and Nevada were on heightened alert, a U.S. military official told CNN.
"Security personnel are on the lookout," said the official, who spoke on condition of anonymity. The measure was ordered late Thursday by Rear Adm. Dixon Smith, commander of the Navy's southwest region.
The official, who was not authorized to release details to the media, declined to discuss security procedures, but said the move was made after it became clear that Dorner gained access this week to the Naval Base at Point Loma and stayed in a motel there.
Two sailors reported Dorner approached them Wednesday and spoke with them for about 10 minutes at a San Diego coastal riverine unit -- a quick, small boat fighting team -- where Dorner served in 2006. As a Navy reservist, Dorner held security jobs at that unit.
The Navy is not certain whether Dorner still possesses any military identification he might try to use to enter a facility.
Earlier this week, the Naval Criminal Investigative Service (NCIS) field offices in San Diego and at Camp Pendleton have provided support to local law enforcement by handing over service records, the U.S. Navy said.
Investigators said they believe Dorner tried to steal a boat from someone in San Diego, according to the LAPD. Dorner "was not successful, and he fled the location," LAPD Chief Charlie Beck said.
A wallet containing Dorner's identification and an LAPD detective's badge was found near the San Diego airport, police said.
Authorities speculate that Dorner, who is familiar with LAPD policies and procedures, may be trying to lead authorities astray by planting clues.
"He understands the way police departments work: the policies, the procedures, the response times,'" said Brandon Webb, a security expert and editor of SOFREP.com, the Special Operations Forces Situation Report.
Meanwhile, in La Palma, California, about 22 miles southeast of Los Angeles, police on Friday searched the home of Dorner's mother. She and a daughter cooperated with investigators, said Lt. Bill Whalen of the Irvine Police Department.
CNN's Chelsea J. Carter, Nick Valencia, AnneClaire Stapleton, Deborah Feyerick, Sara Weisfeldt and Barbara Starr contributed to this report. Paul Vercammen and Stan Wilson reported from Big Bear Lake. Michael Martinez report and wrote from Los Angeles.
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