A 57-year-old San Francisco man has been arrested after his nephew was found dead Friday, the victim of "severe head trauma."

According to San Francisco Police Department spokesperson Officer Grace Gatpandan, at 5:08 p.m. Friday officers were called to a residence on the 1500 block of Sunnydale Avenue, in a public housing complex just steps from the Gleneagles Golf Course.

Gatpandan says that the officers' intention was to perform "well-being check on a citizen." Instead, they found 24-year-old SF man Marcus Douglas "inside the residence suffering from severe head trauma." He was "pronounced deceased at the scene," she says.

The "circumstances of the crime scene" led the San Francisco Medical Examiner to rule Douglas' death a homicide, Gatpandan says.

A subsequent investigation "determined the possible suspect fled the scene in a red vehicle," and witness statements and "other evidence" led police to believe that 57-year-old SF man Broderick Douglas (pictured above), the uncle of the victim, was the man they were looking for.

Gatpandan says that on Saturday, police arrested Douglas on the 1400 block of Palou without incident.

He has been booked at San Francisco County Jail on charges of murder. According to the Ex, this is San Francisco's 19th homicide for 2015.

Just because an arrest has been made does not mean SFPD's done investigating, however. Gatpandan urges anyone with information on this case to call SFPD's Anonymous Tip Line at 415-575-4444 or to text-a-tip to TIP411 with SFPD at the beginning of the message.