The Carla Williams-Mannequin Killer Connection

So, police found the body of Carla Williams blasted in half in the same building my friend saw the ghost. I thought it might be the ghost of Carla, which isn't unreasonable, since that was clearly a female ghost i the picture. Except the body was clearly less old than the ghost. So whose ghost did we see there? And what drew Carla Williams to that spot? And what so savagely ripped her body in two?

What we know: Carla Williams claims to have been possessed by Devil when she hits the cop, which is totally unlike here. She flees her home, also unlike here. At that building where she was found dead, there was probably an exorcism going on there a few weeks ago, but it didn't work because the ghost stuck around, probably a result of that broken salt circle. My friend's friend was probably possessed by that ghost, because he said several days later he just sort of... woke up... in that building, starving and exhausted, and surrounded by a group of people, including two priests. He freaks out and runs away. Shortly thereafter, the body of Carla Williams is found dead there. The Mannequin Killer stops killing around this same time.

Theory: Carla Williams was possessed by a demon when she hit the cop. She went to find a priest that night she disappeared. They tried to exorcise the demon (in the warehouse my friend went to the night she went missing). The exorcism goes wrong. It banishes Carla Williams and keeps in the demon. The demon possessing Carla's Body kills people as the Mannequin Killer, changing the clothes of the victims as a way of bragging that he's stolen Carla's body. Carla's ghost possesses my friend's friend, I don't know why but probably to get her body back because she doesn't like what the demon is doing with it. She finds the priest she originally sought to perform the first exorcism and he brings back up. They lure the demon back to the building and cast it out of Carla's body, and she gets it back, but the demon, furious at having been cast out, rips Carla in half before being pulled back to Hell.

That's my theory, and if right, that priest, whoever he is, needs to practice up on his exorcism skills because he did it wrong the first time and did it too slowly to save Carla the second time. That or the demon was really powerful and simply had a better grip on Carla's body than Carla's own spirit, and a better grip on earth too, giving it time enough to kill her before being cast out. Who knows? Maybe her being ripped in half was even part of casting the demon out because its hold on her was so strong that the act of exorcising it did it.

What are your thoughts? Does it work for you? It makes sense to me, but maybe you have evidence to support it or maybe you see some holes in the theory. Maybe you have a theory of your own. Let me know in the comments.

Stay strange!
-Steve