Suspense Movie

Please if you can help me find this film:
It is about a bad guy who does whatever it takes to accomplish what he wants. He gains the confidence of his friend’s family who happen to be rich. One day when going for a run they both get into a fight. Then his friend falls from a cliff; holding from a rock and he decides not to help him. Eventually he dies. Later in the film, he decides to gain the trust of his mother who kind of falls in love with him. The end of movie is about the mother finding out that the guy is a psycho. She kills him after knowing he was also going to kill her husband.
I hope you guys can help me…The film is very unknown and I think it is from Studio Universal