When Nedrick Young (as Gat Morgan) is first shot, he grabs his chest by the right pectoral. When he grabs his wound later, it has migrated to the lower center abdomen.
When Gat Morgan comes to Steve and Ellen Laceys' apartment, he brandishes a Smith & Wesson .38 special with a 2.5" barrel. When Steve's parole officer arrives, detective Lt. Sims hands the gun that Steve Lacey took from Morgan to parole officer O'Keefe. The revolver now has a 4" barrel and appears to be a Colt Police Positive. Sims is handling the pistol with a pencil up the barrel to avoid getting his finger prints on it. The pistol is still a snub nosed revolver as the gun sight can be plainly seen on the short barrel.
Early in the film, Morgan ducks into a garage to evade the cops. As the camera pans to follow the police car, the shadow of one of the film crew can be seen briefly darting across the front of the garage.