Status Updates From Stone Cold. (Lernmaterialien)

I have no idea how, content-wise, this got rated MG/MG+. It's about a retired army sergeant turned serial killer, and contains some pretty heavy subject matter regarding youth homelessness (sexual abuse is heavily insinuated; enforced prostitution and exploitation is everything but explicitly detailed; illegal street drugs are referenced). Don't get me wrong - it's a GREAT read! But middle grades?! Heavy stuff!

Ooh, creepy! Realistically creepy! (And well-written!)
The cover (alt., same ISBN) I have is ridiculous and put me off this something dreadful. I'm rather grateful for the reading challenge, because kerb/curb appeal here is ZERO! (Disembodied leering, deranged man's face looking down on rough sleepers in an alley)