Yearick, not Crooks, was killed on the roof based on the images that were released. The real shooter/2nd shooter was probably the one on the loose. In any event, the police radio mentioned a 2nd shooter according to the witness. When they breached the building there was already blood in the bathroom. IMHO the blood could not have been from officer Graham, as some are saying, because it was too early in the sequence of events. Plus, the small cut on his hand didn't appear to cause much blood loss. Several different blood analysis techniques should have been used to solve some of these unanswered questions.