Little Indian Girl (spoilers I think)

There is a distorted flashback at the end that shows the incident, but not clearly enough that I could figure out what happened. Someone tells the sheriff on the radio that she's on an Indian reservation where she can't do anything then a little girl yells and a man yells something and we hear a gunshot and see the little girl on the ground. I got the impression that the sheriff shot the girl by accident but I couldn't tell why it happened or even if it was the man who shot the girl. By that point, I really didn't care enough to rewind and watch it again. All you need to know is that a little girl died and the sherriff was blamed, probably without good reason, as the ranch owner implied.