I've only recently started watching exorcism movies. Possession is one of those things that really spooks me a little, so I've mostly avoided it.
This movie had a cool twist though, in the sense that it presented the whole thing in a courtroom setting. The girl who was being exorcised died, and now the priest is on trial for criminal negligence.
I loved the way everything in this movie was portrayed. The story was shot differently depending on which lawyer was talking, and even though it was a "based on a true story" type of thing it didn't come off as super unrealistic.
Well worth a watch.