IRVINE, Calif. — A heavy police presence blocked off a street in a typically quiet Southern California suburb Sunday, as residents adjusted to life in the midst of a huge search for a fugitive whose police and military background and vitriolic online manifesto has put the region on high-alert.
Police are working to protect dozens of families considered targets based on Christopher Dorner’s Facebook rant against those he held responsible for ending his career with the Los Angeles Police Department five years ago.
Dorner, 33, is suspected of killing three people, including one police officer, and on the fourth day of the search, authorities put up a $1 million reward for information leading to his capture.
‘‘We will not tolerate this reign of terror,’’ said Los Angeles Mayor Antonio Villaraigosa.
After days without resolution, Dorner’s fugitive status caused concern and fear among others in the upscale community the FBI consistently ranks among the safest US cities.
‘‘If he did come around this corner, what could happen? We’re in the crossfire, with the cops right there,’’ said Irvine resident Joe Palacio, who lives down the street from a home surrounded by authorities protecting a police captain mentioned in Dorner’s posting.
‘‘I do think about where I would put my family,’’ he said.
The neighborhood has been flooded with authorities since Wednesday. Residents have seen police helicopters circle and cruisers stake out schools. Some have kept their children home. Others no longer walk their dogs at night.
Dorner’s background added to the anxiety. The former LAPD officer also served in the Navy, earning a rifle marksman ribbon and a pistol expert medal. He was assigned to a naval undersea warfare unit and various aviation training units, according to military records.
In his online manifesto, Dorner vowed to use ‘‘every bit of small arms training, demolition, ordnance, and survival training I’ve been given’’ to bring ‘‘warfare’’ to the LAPD.
As tense residents went on with their lives, police looked into a taunting phone call to the father of the woman they believe Dorner killed last week.
Two law enforcement officers who requested anonymity because of the ongoing investigation said they are trying to determine whether Dorner made the call telling retired police Captain Randal Quan that he should have done a better job protecting his daughter.