The Exorcist III (1990)
Dir- William Peter Blatty
George C Scott is a police detective named Bill Kinderman investigating a series of grisly murders committed by a serial killer. Unlike your run of the mill psycho, we have something that may very well tie into the supernatural and the very forces of good and evil. His investigation turns up a copycat killer who is following the wicked deeds of the Gemini Killer, who was executed the night of Regan McNeal's exorcism in the first installment. We learn even more may be happening in this well-made sequel that returns some of the glory and terrors that Exorcist 2 lacked. Scott is compelling, taking the role played by the late Lee J Cobb in the first, but who can forget Brad Dourif in one of his creepiest performances. Well worth a look.