In the beginning it's clearly established that this guy (Dylan Walsh) is a murderous psychopath as he steps over the dead bodies of his most recent family. He shaves off his beard and changes his appearance before he moves into another typical American town as "David Harris". Here, he meets Susan Harding (Sela Ward), a recently divorced mother. They hit it off and six months later he's not only living with her in her house but they're engaged to be married. Then, her oldest son, Michael, comes home from military school to meet him and is suspicious of his intentions. The high schooler senses something is wrong with mom's new boyfriend.
David kills an old lady next door after she says that he looks like a serial killer on America's Most Wanted. He makes it look like an accident. Then, Michael sees him talking to himself like he's crazy, which he is. The mother's sister gets him a job at her real estate office, a job he excels at. But when she wants him to fill out paperwork and give them his social security info, he quits since he doesn't want anything of himself on paper. David even begins to forget his own name. "Who am I supposed to be again?", he asks at one point.
Of course, there were no cell phones or internet when the original 80's movie came out so they had to work that angle in, as well as making the main character of the film not the mother or the Stepfather but a precocious teenage son, presumably to appeal to that demographic.I'm sure if they made this movie a few years ago they would have cast Shia LaBeouf in the role. In the original '87 film the main character was "the girl in danger", Jill Schoelen. The biggest problem is that Walsh's "David Harris" pales in comparison to Terry O'Quinn's "Jerry Blake". Least to say, THE STEPFATHER 2009 is another forgettable remake.