The case against - Spoilers
We, the viewers, know Bannion didn't kill Mrs. Duncan but no one in the world of the movie knows that.
- If they're fighting corruption in that town, why wouldn't Bannion be investigated for Mrs. Duncan's murder?
- When the two other policemen, his boss and partner, arrive at Vince's house they tell him they see he made it there (the Duncan house) before them.
- They had offered to go with him wherever he was going but he turned them down.
- He has no alibi for the time during which she was killed.
- He had been to Mrs. Duncan's house several times; a couple of those times he went after he was expressly told not to go.
- She registered a complaint about him.
- She was killed with the gun he took from Larry. No one knows that, of course, but his fingerprints are probably on the gun.
- He has more of a motive to want her dead than anyone else. All the evidence her death triggers would help catch the people he's been after; the same people who killed his wife.
- Debby, who actually kills her Bertha, is dead and only confessed to Bannion.
- By all accounts Debby didn't know Mrs. Duncan and wouldn't have had any reason to kill her.
- If she was wearing a mink coat, surely she would have had on gloves. Either way, in those days women wore gloves as part of their regular outfits; not just in the winter.
Woman, man! That's the way it should be Tarzan. [Tarzan and his mate]