The most interesting thing about this movie to me is the carefully orchestrated camerawork by Harold E. Stine, the way scenes are blocked and lit to produce a sense of restriction in this story of a serial killer played by Grant Williams. William is under court-ordered psychotherapy by William Leslie, who can't figure out what to make of him. Williams is also carrying on a Production-Code-compliant affair with Shirley Knight, Leslie's niece, when he's not going out to shove an ice pick through the back of a random stranger on a crowded Los Angeles street at precisely 7PM.
Given that the script is by Robert Bloch, there's little doubt that the research was good. Times have changed, however, and we now unhappily know a lot more about the psychology of serial killers than the simplistic motive ascribed here. Within that context, the performances are good, and the can-they-catch-him story is good, but it's more a subdued example of Grand Guignol -- only without the blood, because of the Code.