In my tiny scrambled mind I think
The 3 boys were brothers identified as Crimson, we think one of them broke the window because they were seen running away and the note accuses one of them. This makes you believe it must have been one of them when there is no evidence it was, so it might have been someone else entirely. So Sherlock dosnt interview any of them
@bikergirl Carol I liked the Sherlock Holmes one.
For those that didn't get it the answer was in the note as it said "?Crimson" ... the punctuation mark is called a Question Mark ... so if you replace the symbol the answer was Question Mark Crimson = ?Crimson
@denzarki I liked yours too and the answer me thinks is the word THE as it appears twice