Police are investigating after a 69-year-old man allegedly beat someone to death in his own Brooklyn over the weekend.

Officers are questioning the man, identified by neighbors as Cecil Brown.

Police were called to his apartment on Union Street in Crown Heights around 10 a.m. Sunday regarding an assault.

When they arrived, they found 48-year-old Rodolfo Rosa with severe head trauma.

Rosa, a Virginia native, was taken to the hospital, where he was pronounced dead.

Brown was also taken to be treated for minor injuries.

One neighbor, who did not want to appear on camera, was blindsided by the news.

"It's never any ruckus coming from in the apartment. He's never loud outside, always says hi. Very polite. It's just really shocking," said the neighbor.

It's not clear if Brown knew the man who was killed.

No charges have been filed yet.