Visible crew/equipment: When Glenda electrocutes the security guard and his face bursts into flames, you can see where a flammable substance has been smeared on the prop head. It's sort-of whiteish, and the flames immediately ignite on it.
Visible crew/equipment: When Father Bryce is locking the students in their rooms near the beginning, when he locks Trevor's friend's door, there's a close-up of the door handle. If you look closely, you can see the reflection of the camera with a black covering draped over it.
Answer: They were blamed for the death of Jake's foster brother, which was deemed a terrible accident, and they were sent to the reform school as a punishment. Presumably, when they had to leave the reform school given what happened, they were instead given community service as punishment.
TedStixon