Riddle: One day, there was a dead woman found in her house. On the wall of the room that she was found in, there was one (?) written in her own blood when she was about to die. the police had three suspects, the Stone family who lived next door. The mother, Michelle, said: I was just making breakfast at the time. ( The police had told them the time of the murder). The father, David, said: I was fixing the shed. Their son, Mark, said: I was just playing with my toy car. Who was the murderer?
Answer: The murderer was Mark because of the ? on the wall. Question Mark. Get it?