Richard Mcbeef
The play Richard McBeef (the one written by Seung-hui Cho, the Virginia Tech killer) seems to have been loosely based on this movie. If you read the Richard mcbeef play by Cho, you'll notice some plot similarities (in this movie, the daughter suspects that her stepfather might be a psycho; in Richard McBeef, the son suspects that his stepfather may be a murderer and child molester). I doubt that Cho has seen this movie (it's not particularly well known), but the plot parallels are fairly astonishing if one examines this movie and the play.
http://www.thesmokinggun.com/archive/years/2007/0417071vtech1.html