A witness said the gunman walked up to 45-year-old Ricky Ray Whitfield near Slauson and Deane avenues and shot him once in the head at about 10:30 p.m. Thursday.
The gunman then calmly walked away, got into a white vehicle and drove away, according to police. Whitfield was declared dead at the scene.
The gunman is believed to be in his 30s. A motive has not yet been determined.