A California man and woman say fugitive ex-police officer Christopher Dorner tied them up in the couple's mountain condominium and stole their car before the firefight that led to his presumed death.

Karen and Jim Reynolds said at a news conference Wednesday that they came upon Dorner when they entered the condo Tuesday, and believe he had been there as early as Friday.

They said Dorner had a gun but said he wouldn't hurt them.

Authorities couldn't immediately verify their story, but it matched early reports from law enforcement officials.

The Reynolds say he tied their arms and put pillowcases over their heads before fleeing in their Nissan.

Karen Reynolds managed to get to her cellphone and dialled 911.

Police say Dorner began a "reign of terror" on Feb. 6 after they connected the slayings of a former police captain's daughter and her fiance with an angry manifesto he posted online. Dorner has since been connected to four killings.

The search ended Tuesday when a man believed to be Dorner bolted from hiding, stole two cars, barricaded himself in a vacant cabin and mounted a last stand in a furious shootout with police before the building erupted in flames.

'He was on a mission'

The tourist community of Big Bear Lake that was the focus of the intensive manhunt was returning to normalcy Wednesday, and residents were sharing stories of events of recent weeks.

Rick Heltebrake describes meeting a man he recognized as Dorner while driving in his truck along a rural mountain road.

He said the man emerged from a grove of trees holding a large assault-style rifle, clad in camouflage from head to toe and wearing a bulletproof vest packed with ammunition.

Rick Heltebrake, 61, a Boy Scout camp ranger, with his four-year-old dalmation, Suni, says fugitive Christopher Dorner hijacked his pickup truck while attempting to flee from the Big Bear area of California. (Reed Saxon/Associated Press)

Heltebrake said the man pointed the gun at him and ordered him out of his truck.

"I don't want to hurt you. Start walking and take your dog," Heltebrake recalled Dorner as saying during the carjacking Tuesday.

The man, who wasn't lugging any gear, got into the truck and drove away. Heltebrake, with his three-year-old Dalmatian Suni in tow, called police when he heard a volley of gunfire erupt soon after, and then hid behind a tree.

A short time later, police caught up with the man they believe was Dorner, surrounding the cabin after crashing Heltebrake's truck in the San Bernardino Mountains 130 kilometres east of Los Angeles.

A gunfight ensued 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.

Heltebrake said he wasn't panicked in his meeting with Dorner because he didn't 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.