A suspect was apprehended Monday morning after he allegedly struck an elderly man with a stick in San Francisco's Glen Park, killing him.

The incident happened around 8:15 a.m. Monday, and police say that 53-year-old Peter Rocha assaulted the victim, who was 94 years old, causing him to fall and strike his head. The assault happened on the first block of Elk Street near the southeast corner of Glen Park.

As the Examiner reports, SFPD officers later spotted Rocha from a witness description and detained him at the intersection of Diamond and Bosworth streets.

Rocha was booked on suspicion of murder and is being held without bail in the SF County Jail.

Update: As NBC Bay Area reports, Rocha, a homeless man with apparent mental illness, was well known to residents of the neighborhood for being a menacing presence for about the last year. Police had received multiple reports of Rocha threatening people, but he reportedly had not hurt anyone up to this point.

The victim has been identified as longtime neighborhood resident Leo Hainzl, who emigrated with his family to the U.S. to escape the Nazis in Austria. "He was known by his neighbors for growing tomatoes under the stairs of his home and for his frequent walks with his dog, Fritz," NBC Bay Area tells us.

This was the second homicide this month following the killing of 19-year-old Kelvin Chew in the Portola neighborhood three weeks ago. And this marks the 18th homicide in San Francisco this year.