Serial murder is one of the most baffling crimes that occur in the United States and around the world. Knight (2006) defines serial homicide as the killing of three or more people over a period of more than 30 days, with a significant cooling-off period. The reflection period can last weeks, months or even years. Researchers have proposed various psychological, biological, and sociological theories that offer a partial understanding of the nature of serial murder. Some propose that the basis of criminal behavior is a predisposition to violence as well as a mix of environment, personality traits, and biological factors. Serial killers are predominantly male. Only 3% of serial murders are committed by women (US News and World Report, 1994). Knight (2006) describes a few different personality types of serial killers: the psychopathic, narcissistic, paranoid, or antisocial personality type, or with temporal lobe epilepsy, schizoid personality, and dissociative disorder. Psychotic serial killers are extremely rare. Most serial killers know right from wrong and are not considered crazy. Even Jeffery Dahmer who dismembered his victims and ate their flesh was deemed sane by Dr. Park Elliot Dietz. (Frank, 2000) (Dr. Dietz also considered Andrea Yates sane.) People who kill for money or to escape detection, such as gang or mafia members, are not considered serial killers. I will focus this article on the majority (2/3) of serial killers who have been clinically listed in the Diagnostic and Statistical Manual as having personality disorder type B, classified as antisocial (psycho/sociopathic), histrionic, or narcissistic behavior. The remaining 30 percent of serial killers have one or more other psychoses s...... middle of paper ......emic Search Complete (23218518)US News and World Report. (1994) 116(17) 12 Excerpt from completed academic research (9404267502)Frank, Christina. (2000) Biography. 4(6) 82. Excerpt from completed academic research (3383734)Warf, Barney. (2002) Atrocious spaces, treacherous places: the sinister landscapes of the Serial Killers. Social and cultural geography, 3(3) 323-345. Retrieved from Academic Research Full DOI: 10.1080/1464936022000003550 Antisocial Personality - Part 1. 2000. Harvard mental Health Letter. 17(6) 1-7. Excerpt from Completed Academic Research. (3826533)Buckholtz, Joshua W., Kiehl, Kent A. (2010) Inside the Mind of a Psychopath. Scientific American Mind, 21(4) 22-29 Retrieved from Academic Search Complete (58698958) Dalal, J.S. (2009) A case study of serial killers. Journal of Punjab Academy of Forensic Medicine and Toxicology, 9(2) 109-113 (49019063)