BRISBANE, Calif. (AP) — A resident shot and killed a man inside his home in the San Francisco Bay Area city of Brisbane in what authorities initially said was a home invasion.

Officers were called Monday around 4:20 p.m. to a home in a quiet neighborhood, where they found a man dead from gunshot wounds inside the house, Brisbane police spokeswoman Michelle Moneda.

Moneda said Tuesday that the incident no longer appears to have stemmed from a home invasion or robbery, though she could not provide more information about what happened. Detectives were still trying to determine what happened and whether the shooter and the man who died were related, she said.

The resident was cooperating with police and was not in custody on Tuesday, Moneda said.

Neither of the men's names have been released.