The Prison Prep School Murder Case File 2 - S1-E11
Stupidity: The whole story of the 5 episode arc requires unhealthy amounts of suspension of disbelief; the killer directly challenged the police and announced where and when the murders will take place; at a 3 days prep school camp. Despite that, one of the teachers, a new one at the job even, is allowed to attend the camp wearing a ski mask, supposedly to hide hideous burns, and the police just lets him in without checking. And yes, he's the criminal, not even a red herring. By comparison, in the live version adaptation they check him, and he's wearing prosthetic scars.