Peter discovers that his wife is cheating on him with his be…

Peter discovers that his wife is cheating on him with his best friend. Distraught, he buys a gun and follows her to his friend’s house, where she enters. He walks up to the door, gun in hand, and is about to knock on the door with the intent to shoot them both. But then he has a change of heart and decides this is a bad idea. He gets back in his car and drives away. What crimes, if any, has Peter committed?