Doppelganger

The name of this movie is Doppelganger released in 1993-03-01 and it's main theme is A woman moves from NYC to LA after a murder, in which she is implicated. She is followed by what is apparently her evil alter- ego. She moves into a room for rent by a writer, and he begins having an affair with her, but after some strange things happen, he's not so sure if the affair is with her or her doppelganger..