Is it possible to predict who will become a serial killer? It’s a chilling subject, especially for someone like me who hates horror movies and refuses to watch one second of Friday the 13th. Today, I gave a presentation on Oppositional Defiant Disorder and Conduct Disorder in children & adolescents (which are childhood disorders that can progress to Antisocial Personality Disorder and the feared Sociopath/Psychopath) when my fellow Psychiatry resident mentioned the “MacDonald Triad. ” I’ve never heard of the triad, but I was pleasantly disturbed to learn something new. Apparently, the triad links 3 behavioral characteristics in childhood as predictors of criminal, homicidal behavior in adulthood: animal cruelty, obsession with fire setting, and persistent bedwetting past the age of five. With the help of Google, I found that contract killer Richard “The Iceman” Kuklinski and serial killer Dennis Rader posessed some of these characteristics. Well, I can confidently say that I don’t fit the link nor do I know anyone who does. But then again, I don’t go around asking friends if they have a long history of peeing in bed.