The Psychopath pitches itself somewhere between American Psycho and Dexter and is influenced by both to some small extent.
The cover brief was to find a solution that hinted at the themes of academia and murder. The main protagonist also had clear signs of having Obsessive-Compulsive Disorder which I thought could possibly play a part in the design.
An initial thought I followed for a while was to portray a murder weapon. How about a baseball bat (from P.E.) a compass or sharpened pencil?