Sinister (2012)

A true crime writer moves his family into a new house without telling them it was the scene of a gruesome murder. While digging through old home videos he finds in the attic, he notices a pattern-each reel shows a different family being murdered in disturbing ways, all connected by a creepy figure lurking in the background. As he gets more obsessed with the tapes, strange things start happening around the house. His kids begin acting weird, noises come from the attic, and shadowy figures appear in the dark. The deeper he investigates, the more he realizes these murders aren't isolated-they're part of something older and far more dangerous. The tapes hold clues, but they also seem to be drawing his family into the same cycle of horror.