Hundreds of high school alumni are receiving strange handwritten letters in the mail.
Meridian Township Police say they've been investigating, trying to find out who has been sending them.
Police say they have received dozens of notes. Someone is sending various thank you cards, using different envelopes, but always the same handwriting and same color pen.
The note reads: "Man can never escape from his conscience, you can only deceive others but never yourself."
Meridian Township will not say if the school security increase is related to the postcards.