Neighbors on a quiet cul-de-sac in Maplewood had not seen 90-year-old Ken Bowser in the past couple of months.

But his eldest son, Larry Bowser, 65, who had lived with his dad for at least a decade, told them that his father was suffering from dementia and Alzheimer's disease.

Neither neighbors nor a family member knew what prompted Ken Bowser to fatally shoot Larry about 7:40 p.m. Saturday at their house in the 1200 block of Hilltop Court.

After the shooting, Ken Bowser called 911 and waited for police. Officers at the scene told Bowser to come outside, where they apprehended him without incident, said Maplewood Police Chief Paul Schnell.

Larry Bowser was shot once, and a handgun was recovered, Schnell added.

Sandy Jacobs, who's lived in the other half of the Bowsers' twin home for 12 years, said she heard a single gunshot Saturday evening but no argument or scuffle preceding it. She didn't call 911, thinking perhaps she had heard fireworks.

Maplewood police responded to a shooting Saturday. A 90-year-old man told authorities he shot his son, officials said.

When she noticed the police lights and sirens, though, she knew it had been a gunshot.

Jacobs said she had heard Ken Bowser griping to his son once in a while, but nothing violent or constant, she said.

Schnell said "there's still some confusion" about what led to the shooting. "There is no indication that there was violence that precipitated the situation."

"The focus of investigators, at this point, is to determine exactly what prompted this," Schnell said. "In addition to providing answers … we hope to explore potential strategies to intervene in such cases to prevent lethal acts of intra-familial violence," he added.

Schnell said investigators will forward their findings to the Ramsey County attorney's office on Monday for consideration of charges. In the meantime, Ken Bowser remains jailed without bail.

A judge on Monday will likely order an exam done by a psychiatrist that will determine whether Bowser is competent to appear in court and enter a plea.

A neighborly cul-de-sac

Hilltop Court is a short block of mostly twin homes, just east of Hwy. 61 and south of County Road C, where neighbors sit in lawn chairs outside their garages and often cross the street or their well-kept lawns to chat.

Craig St. Sauver, his wife and their three children moved into the right side of the twin home next door to the Bowsers a year ago. In the left side is Paul Johnson, a retired sketch artist with the state Bureau of Criminal Apprehension who's lived in the area for all of his 74 years.

St. Sauver said he and Larry Bowser talked sports, but Bowser had told him his father was sick. When St. Sauver would see Bowser shoveling snow, he'd tell him that he'd fire up his snowblower and do it for him.

Johnson said Larry Bowser would talk about his dad, telling him, "It's not good, not good, really getting bad.

"He says, 'I don't know what to do,' " Johnson said. When neighbors suggested putting the elder Bowser in a care facility, the son said his dad "won't have any part of it."

The neighbors said Ken Bowser's two daughters stopped by the house every other day or so. Efforts to reach the women Sunday were unsuccessful.

Ken Bowser owned his half of the twin home. Johnson said he'd paid cash for the house after selling a big parcel of property near County Road D to developers. Larry had lived there for years, with his brother Mike living there on and off.

'Maybe something snapped'

A family friend brought Mike Bowser, 60, to the house Sunday afternoon. They circled the property, which was sealed by police, but didn't go in.

"No clue," Mike Bowser said when asked what happened. "I don't know what the situation was. My dad's old, maybe something snapped."

Neighbors said Larry Bowser worked in the Home Improvement Building at the State Fair every year selling carpeting and flooring. They spoke of Larry Bowser as a friendly guy who was always willing to lend a hand.

Although homicides committed by people as old as Ken Bowser are exceedingly rare, according to a CNN report from 2011, 5 to 10 percent of Alzheimer's patients become violent at some point during the progression of the disease.

"If you don't understand what's happening because your brain is not functioning, it can be scary," Beth Kallmeyer, senior director of constituent services at the Alzheimer's Association told CNN. "You might act out, become agitated or violent."

None of the neighbors Sunday knew where Ken Bowser might have gotten a loaded handgun.

About 18 months ago, also in Maplewood, an 84-year-old man shot and killed his 36-year-old son. Pang Se Vang pleaded guilty to second-degree murder and died in jail in October 2014, one week before he was to be sentenced.

Vang told his pastor on the morning of the shooting that he was upset because his son would not install cable television in the home.