A family is looking for answers after an unarmed 73-year-old grandfather was shot and killed by police early Monday in Bakersfield, California.

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Francisco Serna, whose family says he was in the early stages of dementia, was shot and killed while walking early Monday by police responding to an erroneous report of a man brandishing a handgun.

Police had arrived about 12:30 a.m., and when a witness pointed to Serna, one officer fired several rounds and killed him, Bakersfield police spokesman Sgt. Gary Carruesco told KBAK-TV and the Los Angeles Times.

According to the Times, no gun was turned up in a search of the scene, but authorities did find a crucifix. Family members told Time magazine that witnesses may have mistaken the crucifix, which he often waved at people, for a gun.

Carruesco told CBS News' Crimesider in an email that he can't yet say how many times Francisco Serna was shot but that the deceased's son was "misinformed" about the claim of nine he made in a Facebook video.

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Serna’s son said his father had worked at a cotton gin in California’s Central Valley until retiring about a dozen years ago, and that his father did not own a gun.

“My dad did not own a gun. He was a 73-year-old retired grandpa, just living life,” Rogelio Serna told the Times. “He should have been surrounded by family at old age, not surrounded by bullets.”

Rogelio Serna said his father had been suffering from delusions and other early signs of dementia that had appeared to be getting worse in the past month. His father often took late-night walks alone to tire himself out, he said.

Police had visited the house twice before because his confused father activated a medical alarm, Rogelio Serna said.

In a video posted on Facebook, the deceased's son wrote, "My dad was not armed. There's false reports about my father having weapons – he was never armed."

“My father was MURDERED by BAKERSFIELD POLICE DEPARTMENT,” he wrote.

The coroner said an autopsy would be performed on Francisco Serna. The police officer involved has been placed on administrative leave.

– The Associated Press and the Cox Media Group National Content Desk contributed to this report.