Police say they have found charred remains in the rubble of a burnt-down cabin where a murder suspect had been hiding.
Ex-policeman Christopher Dorner, accused of killing three people, was thought to have barricaded himself in and exchanged fire with police.
A single gunshot was later heard inside the building, which then began to burn.
Forensic tests are to be carried out to determine if the remains are those of Mr Dorner.
The gunman had reportedly sworn revenge on police officers he blamed for his sacking in 2008.
The search moved to the area of Big Bear Lake, a ski resort 80 miles (130km) east of Los Angeles, last Thursday after the suspect's burnt-out truck was found there.
San Bernardino County Sheriff's spokeswoman Jodi Miller said charred remains had been found inside the burnt-out cabin, where Mr Dorner is believed to have been holed up, the Associated Press reports.
One officer was killed and another injured in the shoot-out with the suspect at the cabin.
Reports say the police then fired tear gas into the building and used a loudspeaker to urge the gunman to surrender.
Shortly afterwards, a single gunshot was heard inside the building and a fire began to spread through the cabin.
At an earlier news conference, San Bernardino County Sheriff's Cindy Bachman said police believed the man barricaded inside the cabin was Mr Dorner.
LA officials had offered a $1m (£630,000) reward for information leading to Mr Dorner's arrest.
The authorities earlier said that the former officer with Los Angeles Police Department (LAPD) was suspected of killing three people, including a policeman.
Police have been protecting about 50 families, many belonging to former LAPD colleagues, against whom Mr Dorner had vowed revenge for allegedly ruining his career.
In an online manifesto, Mr Dorner, a former US Navy reservist, suggested that racism was rife in the LAPD.
