Conventionally, a “serial killer” is an individual who has killed more than three persons at different times usually with an inert period between the killings. However, the FBI defines a “serial killer” as “a killer who has committed a series of two or more murders, committed as separate events usually but not always, by one offender acting alone.” In most of the cases, the motive behind the killing was attaining some sort of psychological satisfaction. It is mostly on account of some sort of sexual satisfaction sought by the killer. But according to the FBI, the predominant motives behind serial killing are: “anger, thrill, financial gain, and attention seeking.” In serial killings, the mode of murder and the type of victims have something in common with them. Serial killers are distinguished from the mass murderers and spree killers in that the latter kill in a continuous event which may take place in two or more different sites with a notable period between the killings. The serial killer, contrarily, remains dormant during a hiding period following a killing and plans the next cold-blooded murder. Occasionally, the purpose behind such killings is to spread terror in certain communities. Usually, a serial killer repeats the pattern of killing.