MURDER LOGICS

Logic 4

A millionaire was shot in the forehead at home. The detective spoke to the millionaire's 3 sons, Jack, John, and James, who were at home.

Jack said that night John, their father, and he had been at an official reception. They arrived home and entered the living room: his father came in, and then John and Jack. When their father came up to the stairs, James entered the living room and shot their father.John confirmed Jack's information.James said he had visited his friends that night. When he arrived home, his father was already dead.

The detective understood everything immediately. Who was the killer, and how did Stevens resolve that case?

Answer:

John and Jack lied,if James had killed their father, a bullet would have shot him in his nape, because he wanted to go upstairs.