One snowy night, Sherlock Holmes was in his house sitting by a fire. All of a sudden a snowball came crashing through his window, breaking it. Holmes got up and looked out the window just in time to see three neighborhood kids who were brothers run around a corner. Their names were John Crimson, Mark Crimson and Paul Crimson.
The next day Holmes got a note on his door that read "? Crimson. He broke your window."
Which of the three Crimson brothers should Sherlock Holmes question about the incident?

Mystery Puzzle Sherlock Holmes

Mark Crimson "?" = question MARK, so the note on the door reads "Question Mark Crimson. He broke your window."