"The Devil Inside" joins a number of other recent demonic possession horror films to emerge as a legitimate subgenre of horror. Only this film is so concerned with authenticity it's shot like a documentary, in Vatican City, with real experts, very little CG, and a very talented contortionist who gives new meaning to "popping and locking."

NextMovie spoke with "The Devil Inside" director-writer William Brent Bell and producer-writer Matthew Peterman at the film’s premiere last night at Regal LA Live Stadium 14 in downtown Los Angeles.

Exorcism films are very popular nowadays what with "The Last Exorcism," "The Exorcism of Emily Rose," "The Rite" and others. What do you think the lasting appeal is?

William Brent Bell: I guess it’s the ultimate battle between good and evil, you know? Heaven and hell. God and the devil. Everybody in one way or another is affected by religion since the day they’re born, and [exorcism] is all firmly stuck in religion outside of science. So it’s something everybody can relate to. And what we tried to do with the movie is make it believable so that those people who might not believe things could actually maybe see a different side to it, that it’s not so fire and brimstone.

Matthew Peterman: I think people are kind of enamored and in fear of things that there aren’t black and white answers to, and the existence of God and the devil kind of raise those questions. I think people have a definite interest in that.

What sort of tools did you use to make "The Devil Inside" seem more realistic? I know you shot scenes in Vatican City and you interviewed priests, board-certified neurologists, and metaphysicists.

WBB: The way we shot it, this is [supposed to feel like] a semi-professional documentary. The footage we have from 1989, it’s mostly real footage. So instead of trying to recreate things, we tried to find real things that were authentic. As you said, the experts in the film are real people, so instead of scripting stuff and having actors do it, we found the people who we would base our dialogue on and just had them speak about what they know better than we do.

MP: Yeah so it’s a great mix of fact and fiction where you’re watching things that we kind of created but then you’re watching things that either actually happened or real people talking about the subjects that they know about, that they live basically.

Also Check Out: Why Exorcisms Are Awesome

How do you come up with different ways to make someone possessed? The physical changes are what really affect the audience.

WBB: For this film we were trying to keep it as authentic as possible. We kind of on purpose stayed away from things like visual effects and 3-D visual effects especially.

In-camera effects always work better.

WBB: Yes it’s all in-camera and when you’re doing that all of a sudden, not even that you’re trying that hard, you’re like, "Wow, this is better than what I’m used to seeing because it’s real." And then on top of that everything in the film is usually based on something real that we researched with a real priest or real exorcist or what have you. So it was more about us trying to take what their experiences were and recreate them in a movie as if we were there with them with a camera. It’s not necessarily coming up with what would be crazy. I think that makes it come across as much more authentic and unique so it was kind of an easy way to do it maybe.

MP: Yeah I think most people going to see this realize they’re going to see a movie but I know for us when we were making it we just wanted everyone for at least a second to wonder what they’re actually watching and is this really happening? We kept that kind of mission statement in mind and we were able to create a very authentic, realistic film. For instance, Bonnie Morgan [as the possessed Rosa], who is great in the movie, does a lot of popping and weird things with her joints and her back and her neck. So instead of doing it with visual effects, we found a person who could actually break their back. Bonnie is a contortionist. So we actually used real people to do things.

I read that you are both from the same town but you didn’t actually meet until you were in Los Angeles. Is that true?

WBB: We’re both from Lexington, KY. We moved out here separately and met out here like several years after we’d both lived out here.

MP: One of the mutual friends that we [discovered we had] is actually in the film.

WBB: His name is Brian Johnson and he kind of opens up the movie. He’s the detective who does the police crime scene walk through at the beginning of the film. And he’s one of our dearest friends. Brian was friends with my sister and friends with his brother, basically. ["The Devil Inside"] is the film that [Peterman and I] really got to do what we wanted to do because we stayed away from Hollywood and we didn’t bow down to their money, I suppose, because once you do that you kind of have to really, really listen to what they want to do and a lot of times that’s when things get compromised, as was with our first film.

MP: Yeah our producing partner Morris Paulson and us all had a vision for this movie so we just went off and made it completely independently outside the studio system and it’s worked out pretty well so far.