Clad in camouflage from head to toe and wearing a bulletproof vest packed with ammunition, ex-policeman-turned quadruple killer Dorner was just a few feet away, having emerged from a grove of trees holding a large assault-style rifle.
As teams of officers who had sought the fugitive for a week were closing in, Dorner pointed the gun at boy scout camp leader Rick Heltebrake and ordered him out of his truck.
"I don't want to hurt you. Start walking and take your dog," Mr Heltebrake, 61, recalled Dorner saying during the carjacking on Tuesday.
The man got into the truck and drove away and Mr Heltebrake, with his three-year-old dalmatian Suni in tow, called police when he heard a volley of gunfire erupt soon after, then hid behind a tree.
A short time later, police caught up with the man they believe was Dorner, surrounding a cabin where he had taken refuge after crashing Mr Heltebrake's truck in the San Bernardino Mountains 80 miles east of Los Angeles.
A gunfight followed in which one sheriff's deputy was killed and another wounded. After the firefight ended, a SWAT team using an armoured vehicle broke out the cabin's windows and began knocking down walls. A fire started, and later, charred remains believed to be Dorner's were found.
San Bernardino County Sheriff John McMahon said today the fire was not started on purpose. "We did not intentionally burn down that cabin to get Mr. Dorner out," he said.
His deputies lobbed pyrotechnic tear gas into the cabin, and it erupted in flames, he said. Sheriff McMahon did not say directly that the tear gas started the blaze and the cause of the fire was under investigation.
The sheriff said authorities had not positively identified the remains, but all evidence pointed to it being Dorner and the manhunt was considered over.
A wallet and personal items, including a California driving licence with the name Christopher Dorner were found in the cabin debris, an official briefed on the investigation said.
The tourist community of Big Bear Lake that was the focus of the intensive manhunt was returning to normal today, and residents shared stories of the last week's events.
But none was more dramatic than Mr Heltebrake's.
He said he did not panic in his meeting with Dorner because he did not feel the fugitive wanted to hurt him. "He wasn't wild-eyed, just almost professional," he said. "He was on a mission."
"It was clear I wasn't part of his agenda and there were other people down the road that were part of his agenda," he said.
Dorner, 33, had said in a rant that authorities believe he posted on Facebook last week that he expected to die, with the police chasing him, as he carried out a revenge campaign against the Los Angeles Police Department for sacking him.
The end came in the same mountain range where Dorner's trail went cold six days earlier, after his pick-up truck - with guns and camping gear inside - was found abandoned and on fire near Big Bear Lake.
Deputies searched hundreds of cabins in the area and then, in a blinding snowstorm, SWAT teams with bloodhounds and high-tech equipment in tow widened their search.
One of the major remaining questions is how Dorner eluded such an intensive search. Remarkably, the cabin where he hid for at least part of the time was a stone's throw from the searchers' command post.
San Bernardino County Deputy Chief Steve Kovensky said searchers did not see any forced entry to the cabin when it was checked.
Dorner's cover was blown on Tuesday when two women arrived to clean the cabin, said Lt Patrick Foy of California's Fish and Wildlife Department.
With three killings behind him and law enforcement still on the hunt, Dorner did not shoot them. Instead, he tied up the women and stole their purple Nissan.
Sparing the housekeepers would ultimately start the chain of events that would lead to his undoing. One of the women broke free, called authorities and the chase was on.
Mr Heltebrake, a ranger who takes care of a boy scout camp nearby, said he just had lunch and was checking the perimeter of the camp when he saw someone emerge from the trees and instantly recognised Dorner.
In the meantime, officers quickly realised Dorner must have turned on to a side road, but for a few minutes nobody knew he had changed vehicles.
Game wardens then saw Mr Heltebrake's truck making erratic moves and saw a man fitting Dorner's description behind the wheel. Then the shooting started.
Dorner fired at wardens as he drove. A warden then stopped his vehicle and fired multiple rounds at the truck from his high-powered, semi-automatic rifle, but apparently missed.
Out of options after crashing the pick-up, Dorner made a break for a cabin and barricaded himself inside.
With the stand-off under way, officers lobbed tear gas canisters into the cabin. A single shot was heard inside before the cabin was engulfed in flames, said a law enforcement official.
San Bernardino Sheriff's Deputy Jeremiah MacKay was killed, and another deputy, Alexander Collins, was wounded at the cabin.
Police said Dorner went on the run on February 6 after they connected the February 3 murders of a former Los Angeles police captain's daughter and her fiance with his angry manifesto.
Dorner, who is black, claimed he was the subject of racism by the department and was targeted for reporting misconduct within the department.
Hours later Dorner shot at two LAPD officers, grazing one in the head, and then ambushed two Riverside officers, killing Officer Michael Crain.