Updated at the bottom with authorities suspending their search in Big Bear as a result of weather. First posted at 12:20 p.m.

The search for alleged cop killer Christopher Dorner was in its second full day, with rumors swirling about where he might be but no evidence that the suspect is on the prowl.

A possible sighting at the sheriff's Twin Towers jail in downtown L.A. put the facility on lockdown this morning but a search turned up nothing and the employee who said she saw him wasn't 100 percent sure, officials said. The lockdown was lifted.

And still …

… the Los Angeles Police Department today was on tactical alert today.

The status was reinstated at 10:45 a.m., possibly as a result of the Twin Towers situation and a high call load, said Officer Richard French. The department had also been on tactical alert very early in the morning as the search for Dorner continued, he told us.

Cops in Big Bear who found his burned out Nissan Titan truck at 8:35 a.m. yesterday continued to search the area but said tracks led into the woods and the trail got cold.

Police across the country were on the lookout for Dorner, soldiers with automatic rifles kept an eye out for him at the U.S.-Mexico border, and the California Highway Patrol issued a statewide “blue alert” with “extreme” severity and high “urgency:”

LAPD tactical helmets outside police headquarters downtown.; Credit: Ted Soqui for LA Weekly

LAPD tactical helmets outside police headquarters downtown.; Credit: Ted Soqui for LA Weekly

The suspect is considered armed and extremely dangerous.

Norwalk Christian School was closed for a second day because the ex-LAPD officer, fired in 2008 and now allegedly seeking revenge on police and his former employers, mentions the school in his “manifesto” as the site of his first experience with racism.

There have been apparently false sightings of Dorner overnight from San Diego to the San Gabriel Valley.

On Wednesday night police in Irvine announced that Dorner was the suspect in the Sunday slayings of Monica Quan and her fiancé, Keith Lawrence.

Quan's father, retired LAPD Capt. Randy Quan, represented Dorner in his unsuccessful attempt to save his job after he was accused of lying about a use-of-force incident.

Credit: Monica Quan

Credit: Monica Quan

Thursday morning, authorities say, Dorner ambushed a pair of Riverside cops in their patrol car, killing one.

[Update at 5:16 p.m.]: The San Bernardino County Sheriff's Department said in an update early this evening that the search for Dorner in Big Bear would be suspended overnight, partly as a result of weather. Fresh snow was expected today:

The ground search will be suspended overnight. Deputies who have been participating in the ground search will be coming off of the mountain following sundown. Additional patrol deputies from throughout San Bernardino County Sheriff's Department will remain on the mountain and continue patrolling the Big Bear Valley. In addition to the patrol deputies assigned to the Big Bear Station there will be additional 12 two man units. Citizens are urged to immediately call 911 if they see anything suspicious. Residents are advised to open their doors only to those they know, or uniformed law enforcement officers.

Due to the weather, the aerial search will remain grounded throughout the night.

The manhunt will resume at 7 a.m., according to the department's statement.

[With reporting from City News Service / @dennisjromero / djromero@laweekly.com / @LAWeeklyNews]

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