2005-2012 serial killer movie with old lady burning on a house

All i can remember is that it was a movie about a detective trying to find a serial killer, at some point it lead to a house of an old lady which might be a victim and then the detective falls unconscious inside the house and when he wakes up the house is burning with the old lady inside.
I seem to associate this killer with the deadly sins (its for sure not se7en) but i don't know if that's true or not.
Another thing i remember is that at the end, he finds the suspects and they are like a cult or something.
If you have any guess let me know, i know is little information
Thank youu

another thing, the old lady was in a wheelchair too

Sounds like The Ninth Gate (1999)