An 1829 illustration of Irish serial killer William Burke murdering Margery Campbell
A serial killer (also called a serial murderer) is a person who murders two[dubious – discuss] or more people,[1][2] with the killings taking place over a significant period of time.[2][3] The serial killers' psychological gratification is the motivation for the killings, and many serial murders involve sexual contact with the victims at different points during the murder process.[4] The United StatesFederal Bureau of Investigation (FBI) states that the motives of serial killers can include anger, thrill-seeking, financial gain, and attention seeking, and killings may be executed as such.[5] The victims tend to have things in common such as demographic profile, appearance, gender or race.[6] Although a serial killer is a distinct classification that differs from that of a mass murderer, spree killer, or contract killer, there are overlaps between them.
Holmes & Holmes 1998, Serial murder is the killing of two or more people over a period of more than 30 days, with a significant cooling-off period between the murders The baseline number of three victims appears to be most common among those who are the academic authorities in the field. The time frame also appears to be an agreed-upon component of the definition.
Petherick 2005, p. 190 Three killings seem to be required in the most popular definition of serial killing since they are enough to provide a pattern within the killings without being overly restrictive.
Flowers 2012, p. 195 in general, most experts on serial murder require that a minimum of three murders be committed at different times and usually different places for a person to qualify as a serial killer.
Schechter 2012, p. 73 Most experts seem to agree, however, that to qualify as a serial killer, an individual has to slay a minimum of three unrelated victims.
^Geberth 1995, p. ? "The base population was 387 serial murderers, who killed (under various motivations), three or more persons over a period of time with cooling-off periods between the events. The author identified 232 male serial murderers who violated their victims sexually".