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.
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.