Why do people kill each other? This is a question most people ask when they hear that someone has been killed. Sometimes a person kills another person because some part of their brain is wrong; other times it's something much worse. (1:SV;SV.) Serial killers commit heinous crimes because of a couple of things: the person has a personality disorder or because of reduced connectivity within that person's brain. (3:SV:SV.) There is actually no set definition for the term "serial killer." “The term 'serial murders' means a series of three or more murders, at least one of which was committed within the United States, having such common characteristics as to suggest the reasonable possibility that the crimes were committed by the same actor or by same actors.” (as cited by Robert J. Morton and Mark A. Hilts 5) Initially, some psychologists thought it was a series of two to ten murders, each with a cooling-off period in between; this period of reflection is used to recover both the emotional and physical mindset of the killer; its time period is also used to determine between mass murder and serial murder. (1c: SV; SV; SV.) This was the method of determining the definition of "serial killer". The first signs of a serial killer can be caught at a young age. According to Shirley L. Scott, "Because serial killers do not see other people as anything more than objects, the leap between setting fires and killing people is an easy one to make." (Scott 5) This describes one of the signs, which is setting fires just to destroy things. Another sign is nocturnal enuresis; most psychologists believe this is a sign because of the disturbing dreams that some potential serial killers have. Another sign of a serial killer is harming animals. The... center of the paper... all around them; serial killers commit these terrible crimes because of the connectivity of their brains or the way they were raised as children. (1b: SV; SV or SV.) The definition of the word "serial killer" is a series of three to ten murders, each with a rest period. Serial killers remain in many people's minds for years, if not for the rest of their lives. Works Cited Brogaard, Berit, DMSci, PhD, and Kristian Marlow. "The Creation of a Serial Killer." NP, December 7, 2012. Web. October 29, 2013. "Early Signs of Serial Killers." crimemuseum.org. National Museum of Crime and Punishment. 2008. Network. 29 Oct 2013.Ed. Robert J. Morton and Mark A. Hilts. "Serial murder.". FBI and Web. October 29, 2013. Pemment, Jack, M.A. "The Amygdala's to Blame." Np, April 5, 2013. Web. October 29, 2013. Scott, Shirley L. “What Makes Serial Killers Tick?” Crime Library and Web. November 21. 2013.