The disgruntled former officer had been on the run since last week, after allegedly killing three people in southern California.
He had declared war on police officers he blamed for his sacking in 2008.
A former Los Angeles police officer accused of four murders died from a single gunshot wound to the head, apparently by his own bullet, a US official says.
The doctor who examined the dead body of Christopher Dorner concluded that "the cause of death was a single gunshot wound to the head," San Bernardino County coroner Kevin Lacy told a press conference on Friday.
Lacy was providing details from the results of a six-hour autopsy performed on the body of Dorner, who apparently had killed four people, including two police officers.
Initially, it was unclear whether the 33-year-old former Los Angeles Police Department (LAPD) fugitive killed himself, had been hit by an officer's bullet, or had died in a blaze that engulfed a cabin in the US state of California's Big Bear Lake area, during a fierce gunfight with police forces.
"We are not yet able to speak about the manner of death and tell you whether or not it was the result of a self-inflicted wound or another round… while we are still assembling the reports and putting it together, the implication seems to be that the wound that took Christopher Dorner's life was self-inflicted," he added.