This case report describes a man with aggressive and anti-social behaviors, a 47, XYY karyotype, abnormally elevated urinary kryptopyrroles and multiple brain injuries who is now serving a 250 year sentence for the serial murders of 11 women. These multiple abnormal findings have relevance as identifiable precursors for potential violence in such individuals with a history of behavioral disturbance and are discussed on a background of his case history and review of the literature.