Specifically, he was accosted by armed, plainclothes policemen and panicked. (When I see people wearing civilian clothes coming at me with guns, my first reaction wouldn't be "oh, they must be police!" either.) As I recall, he was tackled to the ground and shot in the head execution style. Any eyewitness would have no reason to believe that police were involved, and would conclude that some sort of awful US-style gang-related murder had taken place.