Heavy snow has hampered the second day of a manhunt for a fugitive former policeman wanted as a suspect in three California murders.
As investigators sought clues on Friday to whether Christopher Dorner was hiding in the San Bernardino mountains east of Los Angeles or had slipped away undetected, police across the region continued to chase down unconfirmed sightings and dead-end leads.
Police have said they believe Dorner was carrying multiple weapons, including an assault-style rifle, though a manifesto attributed to him and posted on Facebook suggested he might be more heavily armed.
"Do not deploy airships or gunships. SA-7 Manpads will be waiting," the message said, in a reference to a Russian-made shoulder-launched missile system.
The manhunt focused on the snow-swept wooded hillsides and cabins near the community of Big Bear Lake, a popular ski resort about 130km northeast of Los Angeles where Dorner's pickup truck was found abandoned and set on fire on Thursday.
The vehicle turned up in the mountains hours after police said Dorner exchanged gunfire with two officers, grazing one, and later ambushed two more policemen in their patrol car at a stoplight, killing one and leaving the other badly wounded.
Property records show that Dorner's mother owns a parcel of land in the San Bernardino mountains.
San Bernardino County records show the 2-acre undeveloped parcel, about 56km west of Big Bear Lake, is under the name of Dorner's mother, Nancy.
Cindy Bachman, County sheriff's spokeswoman, said authorities were aware of the land and had visited it several times.
She said there had been no sign of Dorner in the area.
'The ground got frozen'
A former navy lieutenant, Dorner is also suspected in the weekend shooting deaths of a campus security officer and his
fiance, the daughter of a retired Los Angeles police captain who was singled out for blame in Dorner's manifesto for his dismissal from the LAPD.
The heavy snowfall around Big Bear slowed the pace of the manhunt and prevented infrared-equipped helicopters from
returning to the skies.
But a team of more than 100 law-enforcement officers, some of them riding in tractor vehicles and armoured personnel carriers, kept up a ground search with dogs.
John McMahon, San Bernardino county sheriff, said the manhunt would press on "until either we discover that he's left the mountain or we find him."
Search teams initially followed footprints identified as Dorner's that led from the truck into the forest "until we lost them where the ground got frozen and we couldn't continue to track", McMahon said.
A door-to-door search of more than 200 vacant cabins dotting the high country above town was expected to be completed by nightfall.
Ski resorts and businesses in the area remained open, though visitors seemed to acknowledge they were tempting fate.
As speculation mounted that Dorner might have quietly left the mountains, perhaps using his torched truck as a decoy, reports of unconfirmed sightings sprang up across Southern California - from the desert town of Barstow to the seaside city of San Diego.
In Los Angeles, a sheriff's department employee reported seeing a man she thought resembled Dorner in a parking structure outside the city's main jail, prompting a lockdown of the facility while deputies searched the area, sheriff's spokesman Steve Whitmore said.
The jail commander, Paul Pietrantoni, confirmed to reporters that Dorner's ex-wife works at the facility.
Police said they were providing extra security protection for about 40 potential targets mentioned in the online declaration.