Sophisticated Killer

A mysterious man kills many people for pleasure. As a small boy, he kills all his family. He also kills the parents of his fiance, Nancy, who is a beautiful doctor. The father of one of his victim is in jail. For a lot of money, he convinces an inmate who is due for release to kill the mysterious man. The latter finds out about the plan after the inmate kills the whole family that just moved into the house that the mysterious man sold to them. Many policemen are losing their life trying to capture the mysterious man, but he is getting away with it.