Who Broke The Window Mystery

One snowy night Detective Mehul was in his house sitting by a fire. All of a sudden, a snowball came crashing through his window, breaking it. Mehul got up and looked out the window just in time to see three neighbourhood kids who were brothers run around a corner. Their names were John Crimson, Mark Crimson and Paul Crimson.

The next day Detective Mehul got a note on his door that read "? Crimson broke your window."

Which of the three crimson brothers should Detective Mehul question about the incident?

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