Complex sentence: The police officer responsible for the shooting, Joe "Brain" Weekley, is a member of Detroit's SWAT team, and was a frequent subject on A&E, whose film crews were filming the investigation.
Split into simpler sentences: The police officer responsible for the shooting was Joe "Brain" Weekley. He is a member of Detroit's SWAT team and was a frequent subject on A&E, whose film crews were filming the investigation.