The Strangers theory

[Bojangles]

Okay, I have now, officially, watched the movie. It was okay. Some very creepy points. It is possible that the brother is the killer. They have a few things that point toward him. For instance, the locked front door magically unlocking. He's wearing a suit, like you'd wear for a wedding. The brother is not mentioned outside of the marks on the door frame. Against, James gives no expression when he sees the guys face. You'd think he would be surprised.
I might have misunderstood things, but that's how I saw it.

Good points. I'm going to watch this again to freshen up my memory.