Factual error: In the scene where Lt. Exley arrives at the Night Owl after the murder, the patrol officer is wearing a Safariland velcro-fastened handcuff case on his left hip. That style of rounded cuff case was not introduced until the early to mid 70s.
Factual error: During the interrogation room scene, it is very bright in the room looking into the interrogation room, and it is dimmer inside the interrogation room. Although this would mean that the suspect would be able to see everyone watching as for him to just see a reflection, it needs to be bright his side, and darker the other side. True the glass could have been slightly reflective on one side, but the laws of optics still apply.
Factual error: When Kim Basinger is watching the film of Veronica Lake in her house, we hear the dialogue... but the projector is not a sound projector. It can't be a separate audio tape because she only turned off the projector, but the sounds stopped at the same time. (00:41:15)
Chosen answer: A 12g shotgun blast at that range would cause an incredibly bloody death, especially as there is a good chance it hit the man in the face. Exley has killed a person in the line of duty before this, but not in such a spectacular way. And while he may not have meant to kill him he chose to shoot over letting the man escape.
Grumpy Scot