SAN DIEGO (AP) -- A Navy base was briefly locked down and Mexican authorities kept a watch on the border Thursday in a spreading manhunt for a former Los Angeles policeman who is believed to have killed three people and vowed war on law enforcement.
Navy Base Point Loma was sealed off Thursday morning after an employee reported seeing someone who resembled Christopher Dorner, Cmdr. Brad Fagan said.
Dorner checked into a hotel at the base on Tuesday but left the next day, Fagan said.
"At present time, we don't have any reason to believe that he is on the base," Fagan said.
The lockdown was lifted after the base was searched.
Dorner, 33, was a lieutenant in the naval reserve who left the service on Friday with an honorable discharge and may still carry military identification, Fagan said.
Thousands of police officers throughout Southern California and neighboring states hunted for Dorner, who was fired from the LAPD in 2008 and vowed "warfare to those in LAPD uniform" in a rambling online manifesto.
Authorities believe he shot to death the daughter of a former LAPD captain and her fiance on Sunday in an Irvine parking garage, grazed a Los Angeles policeman during a confrontation Thursday morning in Corona and shot two Riverside police officers from ambush a short time later, killing one.
On Thursday morning, Dorner's wallet and photo ID and a law enforcement badge were found on a street near San Diego International Airport.
Dorner was believed to be heavily armed and wearing military-style fatigues and body armor.
Mexican authorities closely watched San Diego's border with Tijuana and were prepared to shoot him in a confrontation, said Alfredo Arenas, international liaison for the Baja California state police.
The FBI and U.S. marshals provided constant updates.
"We're keeping tabs with them every five minutes to see if he comes to Tijuana," Arenas said. "If push comes to shove, they advised us to shoot to the head."
Arenas said the Mexican navy also was alerted, in case Dorner tried to slip over the border by boat.
Dorner is suspected of tying up an 81-year-old man and trying to steal his boat at the Southwestern Yacht Club in San Diego on Wednesday night. He fled when he couldn't start the engine.
The yacht club is about five miles from where Dorner's wallet was found, San Diego police Capt. Terry McManus said.
Associated Press writer Elliot Spagat contributed to this article.