El Cajon, California (CNN)Activists dismayed by the police killing of an unarmed, possibly mentally ill black man in El Cajon, California, demanded Wednesday that authorities release video of the shooting. They also want a federal probe into the man's death. Police have not released the man's name. As of Wednesday afternoon, police had released little information about the incident, aside from a still photograph showing the African-American man, in what authorities describe as a "shooting stance," facing off with two officers in a parking lot.