You’ll really have to use your brain with this Sherlock Holmes riddle.

One snowy night, Sherlock Holmes was at home sitting by the fire. All of a sudden a snowball came crashing through his window.
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?