By GREG RISLING and TAMI ABDOLLAH, Associated Press
BIG BEAR LAKE, Calif. (AP) — All that was left were footprints leading away from Christopher Dorner's burned-out pickup truck, and enormous, snow-covered mountains where he could be hiding among hundreds of cabins, deep canyons and dense woods.
More than 100 officers, including SWAT teams, were driven Friday in glass-enclosed snow machines and armored personnel carriers to hunt for the former Los Angeles police officer suspected of going on a deadly rampage to get back at those he blamed for ending his police career.
With bloodhounds in tow, officers went door to door as snow fell, aware to the reality they could be walking into a trap set by the well-trained former Navy reservist who knows their tactics and strategies as well as they do.
"The bad guy is out there, he has a certain time on you, and a distance. How do you close that?" asked T. Gregory Hall, a retired tactical supervisor for a special emergency response team for the Pennsylvania State Police.
"The bottom line is, when he decides that he is going to make a stand, the operators are in great jeopardy," Hall said.
As authorities weathered heavy snow and freezing temperatures in the mountains, thousands of heavily armed police remained on the lookout throughout California, Nevada, Arizona and northern Mexico.
Police said officers still were guarding more than 40 people mentioned as targets in a rant they said Dorner posted on Facebook. He vowed to use "every bit of small arms training, demolition, ordinance and survival training I've been given" to bring "warfare" to the LAPD and its families.
At noon, police and U.S. marshals accompanied by computer forensics specialists used a search warrant to remove about 10 paper grocery bags of evidence from his mother's single-story house in the Orange County city of La Palma. Dorner's mother and sister cooperated with the search, and a police spokesman said.
The manhunt had Southern California residents on edge. Unconfirmed sightings were reported near Barstow, about 60 miles north of the mountain search, and in downtown Los Angeles.
Some law enforcement officials said he appeared to be everywhere and nowhere, and speculated that he was trying to spread out their resources.
For the time being, their focus was on the mountains 80 miles east of Los Angeles — a snowy wilderness, filled with thick forests and jagged peaks, that creates peril as much for Dorner as the officers hunting him. Bad weather grounded helicopters with heat-sensing technology.
After the discovery of his truck Thursday afternoon, SWAT teams in camouflage started scouring the mountains.
As officers worked through the night, a storm blew in, possibly covering tracks that had led them away from his truck but offering the possibility of a fresh trail to follow.
"The snow is great for tracking folks as well as looking at each individual cabin to see if there's any signs of forced entry," said San Bernardino County Sheriff John McMahon.
The small army hunting him has the advantage of strength in numbers and access to resources, such as special weapons, to bring him in.
In his online rant, Dorner baited authorities.
"Any threat assessments you generate will be useless," it read. "I have the strength and benefits of being unpredictable, unconventional, and unforgiving."
Without the numbers that authorities have, Dorner holds one advantage: the element of surprise.
"He can be behind every tree," Hall said. "He can try to draw them into an ambush area where he backtracks."
Authorities said they do not know how long Dorner had been planning the rampage. It's not clear if he is familiar with the area, or has provisions, clothing or weapons stockpiled in the area. Even with training, days of cold and snow can be punishing.
"Unless he is an expert in living in the California mountains in this time of year, he is going to be hurting," said former Navy SEAL Clint Sparks, who now works in tactical training and security. "Cold is a huge stress factor. ... Not everybody is survivor-man."
Jamie Usera, an attorney in Salem, Ore., who befriended Dorner when they were students and football teammates at Southern Utah University, said he introduced him to the outdoors. Originally from Alaska, Usera said, he taught Dorner about hunting and other outdoor activities.