Fugitive killer Christopher Dorner died from a single gunshot wound to the head as authorities were pumping tear gas into a mountain cabin during a deadly gun battle with sheriff's deputies.
Sheriff John McMahon of San Bernardino County said it appeared the ex-policeman-turned quadruple killer's wound was self-inflicted.
Deputies said they heard one final gunshot from the cabin as it was going up in flames during Tuesday's firefight.
Before he died, Dorner killed one sheriff's deputy and wounded another during the fierce shoot-out.
Authorities were initially unsure whether Dorner killed himself, had been struck by a deputy's bullet or had died in the fire that engulfed the cabin at Big Bear Lake, California, 80 miles east of Los Angeles, during the shootout.
Police also confirmed that Dorner had in fact been hiding in a condominium a stone's throw from their command post during the manhunt.
Sheriff McMahon said Dorner hid there after entering through an unlocked door and never answered the door when deputies came knocking.
The search for Dorner began last week after authorities said he had launched a deadly revenge campaign against the Los Angeles Police Department for sacking him, warning that he would bring "warfare" to officers and their families.
Dorner is said to have killed a couple in Irvine and a police officer in Riverside, as well as the sheriff's deputy in San Bernardino.
In his manifesto posted online, Dorner, a former US Navy reservist, said he had no fear of losing his life and would wage "unconventional and asymmetrical warfare" warning officers: "You will now live the life of the prey."