<P> Ressler served in the U.S. Army as a provost marshal of a platoon of MP s in Aschaffenburg, as he states in his autobiography "Whoever Fights Monsters ." He was in charge of solving such cases as homicides, robberies, and arson . After four years in Germany Ressler decided to leave the position and was reassigned as the Commander of a Criminal Investigation Division (CID) at Fort Sheridan . He then went back to Michigan State to finish his master's in police administration, paid for by the army, in exchange for two more years of service after graduation . After he got his degree, he served a year in Thailand and a year in Fort Sheridan, where he finished out his career with the army as a major, and moved on to the Federal Bureau of Investigation (FBI). </P> <P> Ressler joined the FBI in 1970 and was recruited into the Behavioral Science Unit that deals with drawing up psychological profiles of violent offenders, such as rapists and serial killers, who typically select victims at random . </P> <P> In the early 1980s, Ressler helped to organize the interviews of thirty - six incarcerated serial killers in order to find parallels between such criminals' backgrounds and motives . He was also instrumental in setting up Vi - CAP (Violent Criminal Apprehension Program). This consists of a centralized computer database of information on unsolved homicides . Information is gathered from local police forces and cross-referenced with other unsolved killings across the United States . Working on the basis that most serial killers claim similar victims with a standard method (modus operandi) it hopes to spot early on when a killer is carrying out crimes in different jurisdictions . This was primarily a response to the appearance of nomadic killers who committed crimes in different areas . So long as the killer kept on the move, the police forces in each state would be unaware that there were multiple victims and would just be investigating a single homicide each, unaware that other police forces had similar crimes . Vi - CAP would help individual police forces determine if they were hunting for the same perpetrator so that they could share and correlate information with one another, increasing their chances of identifying a suspect . </P> <P> He worked on many cases of serial homicide such as Jeffrey Dahmer, Ted Bundy, Richard Chase and John Joubert . </P>

When was the term serial killer first coined