He never emerged from the ruins and hours later a charred body was found inside.
"We have reason to believe that it is him," San Bernardino County sheriff's spokeswoman Cynthia Bachman said.
Dorner, 33, had said in a lengthy rant police believe he posted on Facebook that he expected to die in one final, violent confrontation with police, and if it was him in the cabin that's just what happened.
The apparent end came very close to where his trail went cold six days earlier when his burning pickup truck — with guns and camping gear inside — was abandoned on a fire road in the San Bernardino National Forest near the ski resort town of Big Bear Lake.
His footprints led away from the truck and vanished on frozen soil.
With no sign of him and few leads, police offered a $1 million reward to bring him to justice and end a "reign of terror" that had more than 50 families of targeted Los Angeles police officers under round-the-clock protection after he threatened to bring "warfare" to the LAPD, officers and their kin.
Just a few hours after police announced Tuesday that they had fielded more than 1,000 tips with no sign of Dorner, word came that a man matching his description had tied up two people in a Big Bear Lake cabin, stole their car and fled. Authorities didn't immediately give more details on the two people.
Game wardens from the California Department of Fish and Wildlife who were part of the search detail spotted the purple Nissan that had been reported stolen going in the opposite direction and gave chase, department spokesman Lt. Patrick Foy said. The driver looked like Dorner.
They lost the purple car after it passed a school bus and turned onto a side road, but two other Fish and Wildlife patrols turned up that road a short time later, and were searching for the car when a white pickup truck sped erratically toward the wardens.
"He took a close look at the driver and realized it was the suspect," Foy said.
Dorner, who allegedly stole the pickup truck at gunpoint after crashing the first car, rolled down a window and opened fire on the wardens, striking a warden's truck more than a dozen times.
One of the wardens shot at the suspect as he rounded a curve in the road. It's unclear if he hit him, but the stolen pickup careened off the road and crashed in a snow bank. Dorner then ran on foot to the cabin where he barricaded himself and got in a shootout with San Bernardino County sheriff's deputies and other officers who arrived.
Two deputies were shot, one fatally.
A SWAT team surrounded the cabin and used an armored vehicle to break out the cabin windows, said a law enforcement official who requested anonymity because the investigation was ongoing. The officers then pumped a gas into the cabin and blasted a message over a loudspeaker: "Surrender or come out."
The armored vehicle then tore down each of the cabin's four walls.
A single shot was heard inside before the cabin was engulfed in flames, the law enforcement official told The Associated Press.
Until Tuesday, authorities weren't sure Dorner was still in Big Bear Lake, where his pickup truck was found within walking distance from the cabin where he hid.
Even door-to-door searches failed to turn up any trace of him in the quiet, bucolic neighborhood where children were playing in the snow Tuesday night.
With many searchers leaving town amid speculation he was long gone, the command center across the street was taken down Monday.
Ron Erickson, whose house is only about quarter mile away, said officers interrogated him to make sure he wasn't being held hostage. Erickson himself had been keeping a nervous watch on his neighborhood, but he never saw the hulking Dorner.
"I looked at all the cabins that backed the national forest and I just didn't think to look at the one across from the command post," he said. "It didn't cross my mind. It just didn't."
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 his angry manifesto.
Dorner blamed LAPD Capt. Randal Quan for providing poor representation before the police disciplinary board that fired him for filing a false report.
Dorner, who is black, claimed in his online rant that he was the subject of racism by the department and was targeted for doing the right thing.
Chief Charlie Beck, who initially dismissed Dorner's allegations, said he would reopen the investigation into his firing — not to appease the ex-officer, but to restore confidence in the black community, which had a long fractured relationship with police that has improved in recent years.
Dorner vowed to get even with those who had 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."
Within hours of being named as a suspect in the killings, the 6-foot, 270-pounder described as armed and "extremely dangerous," tried unsuccessfully to steal a boat in San Diego to flee to Mexico. After leaving a trail of evidence, he headed north where he opened fire on two patrol cars in Riverside County, shooting three officers and killing one.
With a description of his car broadcast all over the Southwest and Mexico, he managed to get to the mountains 80 miles east of Los Angeles where his burning truck was found with a broken axle.
Only a short distance from the truck, he spent his final days with a front-row seat to the search mobilized right outside.