The Stepfather(2009)

When troubled teen Michael returns home after a year at military school, he finds his mother, Susan, in love and his soon-to-be stepfather, David, has moved into their home. David says he wants them to become the perfect family. But as they get to know each other, Michael quickly becomes convinced that David himself is far from perfect. Trying to verify what he knows of David's past, Michael finds things that don't add up. As strange events and David's bursts of malevolence become more frequent, Michael tells his mother and girlfriend of his suspicions, but they just think he's being paranoid. Eventually, as Michael searches for proof that his suspicions are well-founded, cracks begin to show in David's perfect facade and it becomes apparent he will stop at nothing to keep his secrets. For David has a history of trying to create the perfect family. And each time, when it becomes apparent that perfection is impossible, David has a terrifying way of clearing the slate and starting over.