Proof of the Devil (2015)

Three years ago, Jesse, a seemingly-ordinary boy branded 'The Butcher', committed a gruesome series of murders. Having ended in his capture and execution on death row, Jesse was found guilty on all accounts. Years on, Kate, the boy's mother is determined to prove her son's innocence: how he was not insane, but instead possessed by a terrifying demon. Inviting a film crew into her home, the TV crew start documenting exceptionally strange happenings. Soon enough the truth becomes very clear, as Kate unearths proof of the devil himself.