Police responded early Monday to a report of a man with a revolver acting strangely, said Bakersfield Assistant Police Chief Lyle Martin.
Francisco Serna was shot after police said he failed to respond to orders to stop approaching and remove his hands from his jacket.
One of the seven officers who responded to the call, Reagan Selman, fired seven shots at Serna, who died at the scene.
Serna was not armed at the time of the shooting and police did not find a gun, Martin said. A police statement said a dark-colored simulated wood crucifix was found on Serna.
'A tragic incident'
"BDP murdered my father for no reason," daughter Laura Serna told CNN affiliate KERO
. CNN reached out to members of the Serna family on Tuesday night but didn't get a response.
Eight detectives are looking into the shooting, Martin said.
"I cannot tell you enough that this community is affected by Mr. Serna losing his life," Martin told reporters. "This is a tragic incident for their family, for the community as a whole, and for the police department."
A woman who answered a phone number listed for Selman's wife said they didn't want to comment.
Officers on leave
All seven officers are on leave, Martin said. CNN called the police benevolent association, which will support the officers during the investigation, for comment but didn't get a response.
The people who called the police Monday morning lived across the street from Serna. A woman told detectives she was dropped off at home about 12:35 a.m when a man approached her in her driveway and asked about where she lived.
She thought she saw a dark brown or black handle of a gun, went inside and told her husband to call police. He told a 911 operator the man had a revolver.
Police arrived six minutes later and when the woman saw Serna come out of his house, she said, "That's him," according to the police statement.
Serna came across the street and Selman, who has been with the department since July 2015, fired as Serna was about 15 to 20 feet from him.
No other officer fired and no lower levels of force were attempted, said Martin, who becomes chief on Wednesday. Martin said that in the 20 to 30 seconds between the neighbor saying "that's him" and the first shot, officers were taking cover, giving commands and putting together a plan.
Dispatcher: Serna has dementia
CNN affiliate KBAK
reported that Serna's family said he would take short walks around the area near his house when he couldn't sleep.
CNN affiliates said Serna's family told them he had early onset dementia and was on medication. The family also claimed that the police department knew Serna had dementia, but Martin says he didn't know. However, in an audio recording obtained by KERO, a dispatcher can be heard saying that Serna was "reported as to having dementia."