Perry Mason: The Case of the All-Star Assassin

Thatcher Horton is owner of a Denver sports arena and a couple of sports teams. Bobby Spencer a friend of Ken was one of his hockey players. It seems that Horton verbally promised him that he would take care of him if he gets injured, which happened. Now it seems that Horton is reneging and he has asked Ken to represent him in his suit against Horton. Bobby threatened Horton and not long after that Horton was killed and the murder weapon was found in Bobby's possession. So Perry comes to help defend Bobby. It seems that Horton was not liked by other people including his wife and son, and it also seems that the killer was a professional assassin, so did one of them hire him?