Somebody wrote it. Everyone writes; everyone has habits.
Read closely enough, and the writing itself will name the writer.
THE CASE FILES
Each case asks for more than the last. Two habits name the writer in Case 1; by Case 3 you will need three before the Chief signs anything.
How it works
Read the anonymous writing. Tap anything that looks like a habit, and name it.
With habits in hand, go out and read what each suspect has put their name to. Tap where a habit turns up again.
The hit list keeps score. When one name has the full set, accuse. You have two warrants.
CASE 1
MERIT is your standing as a detective. +10 for every habit you name in the anonymous writing and every match you spot in a suspect's own, +1 for correctly calling a phrase plain, −3 for a wrong call, −25 for accusing the wrong person, +40 for the conviction and +20 for each warrant you still hold at the end.