I don't know what led police to believe he had a gun.
Police shot and killed Francisco Serna, 73, after neighbors reported that he brandished a gun at them.
But police only found a large crucifix on Serna after the shooting, USA Today reports.
Serna suffered from dementia, his son Frank told our partners at KBAK. Serna "opposed firearms" and did not own one, the son said.
Early Monday morning, one of Serna's neighbors saw him standing behind her with his hand hidden inside his jacket. Serna demanded that she let him look inside her car.
The neighbor saw a "dark brown or black-handled object" she thought was a gun, and told her husband to call police. He told 911 that Serna had a revolver.
When police arrived, Serna's hand was still in his jacket. Officers told him to show his hands. He didn't comply and was shot seven times.
BPD [Bakersfield Police Department] murdered my father for no reason.
The role of dementia
Frank Serna said his father often went on walks when he had trouble sleeping, to make himself more tired.
Beth Kallmyer, the Alzheimer's Association vice president of constituent services, said dementia patients often get lost or confused when out on walks.
WATCH | Serna's family was outraged at the shooting, demanding that police be held accountable. The Bakersfield Police Department is listed as one of the deadliest in the United States by Mapping Police Violence.
The family held a candlelight vigil Tuesday night outside Serna's home.