A Northridge, Calif., home improvement store was evacuated tonight because of a possible sighting of suspected cop-killer Christopher Dorner, just hours after police announced a $1 million reward for information leading to his arrest. 
 
 As helicopters hovered overhead and a command center was established, police searched the Lowe's store and eventually told shoppers they could leave, but could not take their cars out of the parking lot. 
 
 LAPD spokesman Gus Villanueva said the major response to the possible sighting was a precaution, but couldn't say whether Dorner was in the area. 
 
 The announcement of the $1 million reward today came as authorities in Big Bear, Calif., scaled back their search for Dorner, the disgruntled ex-cop who is suspected in three revenge killings. 
 
 "This is the largest local reward ever offered, to our knowledge," Los Angeles Police Chief Charlie Beck said at a news conference today. "This is an act of domestic terrorism. This is a man who has targeted those that we entrust to protect the public. His actions cannot go unanswered." 
 
 The money for the reward was pooled by businesses, government, local law enforcement leaders and individual donors, Beck said. 
 
 PHOTOS: Former LAPD Officer Suspected in Shootings 
 
 The reward comes on the fourth day of a manhunt for Dorner, who has left Southern California on edge after he allegedly went on a killing spree last week to avenge his firing from the police force. Dorner outlined his grievances in a 6,000 word so-called "manifesto" and said he will keep killing until the truth is known about his case. 
 
 Dorner's threats have prompted the LAPD to provide more than 50 law enforcement families with security and surveillance detail, Beck said. 
 
 Authorities are chasing leads, however they declined to say where in order to not impede the investigation. 
 
 Dorner's burned-out truck was found Thursday near Big Bear Lake, a popular skiing destination located 80 miles northeast of Los Angeles. 
 
 Investigators found two AR-15 assault rifles in the burned-out truck Dorner abandoned, sources told ABC News. 
 
 The truck had a broken axle, which may be the reason he decided to set fire to it, the police sources said. 
 
 Full Coverage: Christopher Jordan Dorner 
 
 Officers have spent the past couple of days going door-to-door and searching vacant cabins. The manhunt was scaled back to 25 officers and one helicopter in the resort town today, according to the San Bernadino Sheriff's Office. 
 
 On Saturday, Beck announced he would reopen the investigation into Dorner's firing but said the decision was not made to "appease" the fugitive ex-cop. 
 
 "I feel we need to also publicly address Dorner's allegations regarding his termination of employment, and to do so I have directed our Professionals Standards Bureau and my Special Assistant for Constitutional Policing to completely review the Dorner complaint of 2007; To include a re-examination of all evidence and a re-interview of witnesses," Beck said. "We will also investigate any allegations made in his manifesto which were not included in his original complaint." 
 
 Dorner is suspected of killing Monica Quan and her fiancé Keith Lawrence last Sunday in their car in the parking lot of their Irvine, Calif., condominium complex. Both were struck with multiple gunshot wounds. 
 
 Quan's father, Randal Quan, was a retired captain with the LAPD and attorney who represented Dorner before a police review board that led to Dorner's dismissal from the force in 2008. 
 
 On Wednesday, after Dorner was identified as a suspect in the double murder, police believe he ambushed two Riverside police officers, killing one and wounding the other. 
 
 The next day, Randal Quan reported he received a taunting call from a man claiming to be Dorner who told him that he "should have done a better job of protecting his daughter," according to court documents documents. 
 
 Anyone with information leading to the arrest of Christopher Dorner is asked to call the LAPD task force at 213-486-6860. 
 
 ABC News' Dean Schabner, Jack Date, Pierre Thomas, Jason Ryan and Clayton Sandell and The Associated Press contributed to this report. ||||| The bustling winter resort of Big Bear took on the appearance of a ghost town Thursday as surveillance aircraft buzzed overhead and police in tactical gear and carrying rifles patrolled mountain roads in convoys of SUVs, while others stood guard along major intersections. 
 
 Even before authorities had confirmed that the torched pickup truck discovered on a quiet forest road belonged to suspected gunman Christopher Dorner, 33, officials had ordered an emergency lockdown of local businesses, homes and the town's popular ski resorts. Parents were told to pick up their children from school, as rolling yellow buses might pose a target to an unpredictable fugitive on the run. 
 
 By nightfall, many residents had barricaded their doors as they prepared for a long, anxious evening. 
 
 PHOTOS: A tense manhunt amid tragic deaths 
 
 "We're all just stressed," said Andrea Burtons as she stocked up on provisions at a convenience store. "I have to go pick up my brother and get him home where we're safe." 
 
 Police ordered the lockdown about 9:30 a.m. as authorities throughout Southern California launched an immense manhunt for the former lawman, who is accused of killing three people as part of a long-standing grudge against the LAPD. Dorner is believed to have penned a long, angry manifesto on Facebook saying that he was unfairly fired from the force and was now seeking vengeance. 
 
 Big Bear manhunt: In the Feb. 8 LATExtra section, an article about the manhunt for ex-LAPD officer Christopher Dorner said that Big Bear has roughly 400 homes, and that authorities guessed that only 40% are occupied year-round. In fact, authorities planned to search 400 homes, of which 40% are vacation homes not occupied year-round. Big Bear Lake, where the search is taking place, has about 9,000 homes, according to the 2010 Census 
 
 Forest lands surrounding Big Bear Lake are cross-hatched with fire roads and trails leading in all directions, and the snow-capped mountains can provide both cover and extreme challenges to a fugitive on foot. It was unclear whether Dorner was prepared for such rugged terrain. 
 
 Footprints were found leading from Dorner's burned pickup truck into the snow off Forest Road 2N10 and Club View Drive in Big Bear Lake. 
 
 San Bernardino County Sheriff John McMahon said that although authorities had deployed 125 officers for tracking and door-to-door searches, officers had to be mindful that the suspect may have set a trap. 
 
 "Certainly. There's always that concern and we're extremely careful and we're worried about this individual," McMahon said. "We're taking every precaution we can." 
 
 PHOTOS: A fugitive's life on Facebook 
 
 Big Bear has roughly 400 homes, but authorities guessed that only 40% are occupied year-round. 
 
 The search will probably play out with the backdrop of a winter storm that is expected to hit the area after midnight. 
 
 Up to 6 inches of snow could blanket local mountains, the National Weather Service said. 
 
 FULL COVERAGE: Sweeping manhunt for rampaging ex-cop 
 
 Gusts up to 50 mph could hit the region, said National Weather Service meteorologist Mark Moede, creating a wind-chill factor of 15 to 20 degrees. 
 
 Extra patrols were brought in to check vehicles coming and going from Big Bear, McMahon said, but no vehicles had been reported stolen.
– Authorities may have found Christopher Dorner's burned-out truck near Big Bear Lake in California, but the former cop and suspected murderer remains at large this morning, reports the Los Angeles Times. A storm has brought heavy snow and bitter-cold temperatures to the area, which is both a help and a hindrance to the manhunt. Dorner would need serious survival gear if he is indeed still in the woods somewhere. His mother owns undeveloped land in the region, but a search of it turned up nothing. Of course, given Dorner's boasts of planning to bring "warfare" to the LAPD, authorities have to be on guard that they're not walking into a trap, reports AP. Or that he didn't plant the truck there to divert resources while he heads elsewhere. "It makes you wonder," says a former LAPD official. "What is his plan for the end game?"