BIG BEAR, Calif. — The extraordinary manhunt for the former Los Angeles police officer suspected of three murders converged Tuesday on a mountain cabin where authorities believe he barricaded himself inside, engaged in a shootout that killed a deputy and then never emerged as the home went up in flames.

A single gunshot was heard from within, and a charred body was found inside.

If the man inside proves to be Christopher Dorner, as authorities suspect, the search for the most wanted man in America over the last week would have ended the way he had expected — death, with the police pursuing him.

Thousands of officers had been on the hunt for the former Navy reservist since police said he launched a campaign to exact revenge against the Los Angeles Police Department for his firing. They say he threatened to bring "warfare" to officers and their families, spreading fear and setting off a search for him across the Southwest and Mexico.

"Enough is enough. It's time for you to turn yourself in. It's time to stop the bloodshed," LAPD Cmdr. Andrew Smith said at a news conference held outside police headquarters in Los Angeles, a starkly different atmosphere than last week when officials briefed the news media under tight security with Dorner on the loose.

A short time after Smith spoke Tuesday, smoke began to rise from the cabin in the snow-covered woods near Big Bear Lake, a resort town about 80 miles east of Los Angeles. Flames then engulfed the building — images that were broadcast on live television around the world. TV helicopters showed the fire burning freely with no apparent effort to extinguish it.

"We have reason to believe that it is him," said San Bernardino County sheriff's spokeswoman Cynthia Bachman, adding that she didn't know how the fire started. She noted there was gunfire between the person in the cabin and officers around the home before the blaze began.

Until Tuesday, authorities didn't know whether Dorner was still near Big Bear Lake, where they found his burned-out pickup last week.

Around 12:20 p.m. Tuesday, deputies got a report of a stolen pickup truck, authorities said. The location was directly across the street from where law enforcement set up their command post on Thursday and not far from where Dorner's pickup was abandoned. The owner of the vehicle taken Tuesday described the suspect as looking similar to Dorner.

A warden for the California Department of Fish and Wildlife traveling down Highway 38 recognized a man who fit Dorner's description traveling in the opposite direction. The officer pursued the vehicle and there was a shooting at 12:42 p.m. in which the wildlife vehicle was hit numerous times and the suspect escaped on foot after crashing his truck.

After holing up in the cabin, there was a second gunbattle with San Bernardino County deputies, two of whom were shot. One died and the other was expected to live after undergoing surgery.

"We're heartbroken," Big Bear Lake Mayor Jay Obernolte said of the deputy's death and the wounding of his colleague. "Words can't express how grateful we are for the sacrifice those men have made in defense of the community and our thoughts and prayers are with them and their families."

The man believed to be Dorner never came out of the cabin, and a single shot was heard inside before the cabin was engulfed in flames, a law enforcement official told The Associated Press.

The official later told the AP that a charred body was found in the burned cabin. The official requested anonymity because of the ongoing investigation.

Officials were waiting for the fire to burn out before approaching the ruins to search for a body.

Police say Dorner began his run on Feb. 6 after they connected the slayings of a former police captain's daughter and her fiance with an angry Facebook rant they said he posted. Threats against the LAPD led officials to assign officers to protect officers and their families.

Within hours of the release of photos of the 6-foot, 270-pounder described as armed and "extremely dangerous," police say, Dorner unsuccessfully tried to steal a boat in San Diego to flee to Mexico and opened fire on two patrol cars in Riverside County, shooting three officers and killing one.

Jumpy officers guarding one of the targets named in the rant shot and injured two women delivering newspapers Thursday in Torrance because they mistook their pickup truck for Dorner's.

Police found weapons and camping gear inside the charred truck in Big Bear. Helicopters using heat-seeking technology searched the forest from above while scores of officers, some using bloodhounds, scoured the ground and checked hundreds of vacation cabins — many vacant this time of year — in the area.

A snowstorm hindered the search and may have helped cover his tracks, though authorities were hopeful he would leave fresh footprints if hiding in the wilderness.

Dorner's anger with the department dated back at least five years, when he was fired for filing a false report accusing his training officer of kicking a mentally ill suspect. Dorner, who is black, claimed in the rant that he was the subject of racism by the department and fired for doing the right thing.

He said he would get even with those who wronged him as part of his plan to reclaim his good name.

"You're going to see what a whistleblower can do when you take everything from him especially his NAME!!!" the rant said. "You have awoken a sleeping giant."

Chief Charlie Beck, who initially dismissed the allegations in the rant, said reopened the investigation into his firing — not to appease the ex-officer, but to restore confidence in the black community, which long had a fractured relationship with police that has improved in recent years.

One of the targets listed in the manifesto was former LAPD Capt. Randal Quan, who represented Dorner before the disciplinary board. Dorner claimed he put the interests of the department above his.

The first victims were Quan's daughter, Monica Quan, 28, a college basketball coach, and her fiance, Keith Lawrence, 27. They were shot multiple times in their car in a parking garage near their Orange County condo.

Dorner served in the Navy, earning a rifle marksman ribbon and pistol expert medal. He was assigned to a naval undersea warfare unit and various aviation training units, according to military records. He took leave from the LAPD for a six-month deployment to Bahrain in 2006 and 2007.

He left the service on Feb. 1.