Do some research. The authorities did. He stopped his car. Called 911. Told them who he was and that he didn’t know what he hit. Was told by 911 that it was probably a deer - common in the area. Went to look for the thing he hit and didn’t find anything. Investigators investigated for 5 plus months.
https://www.grandforksherald.com/news/government-and-politics/6892941-South-Dakotas-attorney-general-charged-in-crash-that-killed-pedestrian