(Sioux City, Iowa (AP) — A Sioux City man has been given 25 years in prison for trying to kill a police informant. The Sioux City Journal reports that Isaac McDonald was sentenced Wednesday in U.S. District Court in Sioux City. He’d pleaded guilty to conspiracy to tamper with a witness by attempting to kill a person and guilty to other crimes. Authorities say McDonald shot John Mercure in the head on Aug. 1 as he passed the car Mercure was driving in Sioux City. Mercure, who was believed to be speaking to police about drug trafficking and firearms, survived after crashing his car into a tree.