A serial killer is typically a person who murders three or more persons, with the murders taking place over more than a month and including a significant period of time between them. While most authorities set a threshold of three murders, others extend it to four or lessen it to two.
Psychological gratification is the usual motive for serial killing, and many serial murders involve sexual contact with the victim. The Federal 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. The victims may have something in common; for example, demographic profile, appearance, gender or race. Often the FBI will focus on a particular pattern serial killers follow. Based on this pattern, this will give key clues into finding the killer along with their motives.
Although a serial killer is a distinct classification that differs from that of a mass murderer, spree killer, or contract killer, there exist conceptual overlaps between them. Some debate exists on the specific criteria for each category, especially with regard to the distinction between spree killers and serial killers.
The English term and concept of serial killer are commonly attributed to former FBI Special agent Robert Ressler, who used the term serial homicide in 1974 in a lecture at Police Staff Academy in Bramshill, Hampshire, England, United Kingdom. Author Ann Rule postulates in her 2004 book Kiss Me, Kill Me, that the English-language credit for coining the term goes to LAPD detective Pierce Brooks, who created the Violent Criminal Apprehension Program (ViCAP) system in 1985.
The German term and concept were coined by criminologist Ernst Gennat, who described Peter Kürten as a Serienmörder ('serial-murderer') in his article "Die Düsseldorfer Sexualverbrechen" (1930). In his book, Serial Killers: The Method and Madness of Monsters (2004), criminal justice historian Peter Vronsky notes that while Ressler might have coined the English term "serial homicide" within the law in 1974, the terms serial murder and serial murderer appear in John Brophy's book The Meaning of Murder (1966). The Washington, D.C., newspaper Evening Star, in a 1967 review of the book:
There is the mass murderer, or what he [Brophy] calls the "serial" killer, who may be actuated by greed, such as insurance, or retention or growth of power, like the Medicis of Renaissance Italy, or Landru, the "bluebeard" of the World War I period, who murdered numerous wives after taking their money.
Vronsky states that the term serial killing first entered into broader American popular usage when published in The New York Times in the spring of 1981, to describe Atlanta serial killer Wayne Williams. Subsequently, throughout the 1980s, the term was used again in the pages of The New York Times, one of the major national news publications of the United States, on 233 occasions. By the end of the 1990s, the use of the term had increased to 2,514 instances in the paper.
When defining serial killers, researchers generally use "three or more murders" as the baseline, considering it sufficient to provide a pattern without being overly restrictive. Independent of the number of murders, they need to have been committed at different times, and are usually committed in different places. The lack of a cooling-off period (a significant break between the murders) marks the difference between a spree killer and a serial killer. The category has, however, been found to be of no real value to law enforcement, because of definitional problems relating to the concept of a "cooling-off period". Cases of extended bouts of sequential killings over periods of weeks or months with no apparent "cooling off period" or "return to normality" have caused some experts to suggest a hybrid category of "spree-serial killer".
In Controversial Issues in Criminology, Fuller and Hickey write that "[t]he element of time involved between murderous acts is primary in the differentiation of serial, mass, and spree murderers", later elaborating that spree killers "will engage in the killing acts for days or weeks" while the "methods of murder and types of victims vary". Andrew Cunanan is given as an example of spree killing, while Charles Whitman is mentioned in connection with mass murder, and Jeffrey Dahmer with serial killing.
The Federal Bureau of Investigation (FBI) defines serial killing as "a series of two or more murders, committed as separate events, usually, but not always, by one offender acting alone". In 2005, the FBI hosted a multi-disciplinary symposium in San Antonio, Texas, which brought together 135 experts on serial murder from a variety of fields and specialties with the goal of identifying the commonalities of knowledge regarding serial murder. The group also settled on a definition of serial murder which FBI investigators widely accept as their standard: "The unlawful killing of two or more victims by the same offender(s) in separate events". The definition does not consider the motivation for killing nor define a cooling-off period.
Historical criminologists suggest that there have been serial killers throughout history. Some sources suggest that legends such as werewolves and vampires were inspired by medieval serial killers. In Africa, there have been periodic outbreaks of murder by Lion and Leopard men.
In his 1886 book, Psychopathia Sexualis, psychiatrist Richard von Krafft-Ebing noted a case of a serial murderer in the 1870s, a Frenchman named Eusebius Pieydagnelle who had a sexual obsession with blood and confessed to murdering six people.
The unidentified killer Jack the Ripper, who has been called the first modern serial killer, killed at least five women, and possibly more, in London in 1888. He was the subject of a massive manhunt and investigation by the Metropolitan Police, during which many modern criminal investigation techniques were pioneered. A large team of policemen conducted house-to-house inquiries, forensic material was collected and suspects were identified and traced. Police surgeon Thomas Bond assembled one of the earliest character profiles of the offender.
The Ripper murders also marked an important watershed in the treatment of crime by journalists. While not the first serial killer in history, Jack the Ripper's case was the first to create a worldwide media frenzy. The dramatic murders of financially destitute women in the midst of the wealth of London focused the media's attention on the plight of the urban poor and gained coverage worldwide. Jack the Ripper has also been called the most infamous serial killer of all time, and his legend has spawned hundreds of theories on his real identity and many works of fiction.
H. H. Holmes was one of the first documented modern serial killers in the United States, responsible for the death of at least nine victims in the early 1890s. The case gained notoriety and wide publicity through possibly sensationalized accounts in William Randolph Hearst's newspapers. At the same time in France, Joseph Vacher became known as "The French Ripper" after killing and mutilating 11 women and children. He was executed in 1898 after confessing to his crimes.
The serial killing phenomenon in the United States was especially prominent from 1970 to 2000, which has been described as the "golden age of serial murder." The cause of the spike in serial killings has been attributed to urbanization, which put people in close proximity and offered anonymity.
The number of active serial killers in the country peaked in 1989 and has been steadily trending downward since, coinciding with an overall decrease in crime in the United States since that time. The decline in serial killers has no known single cause but is attributed to a number of factors. Mike Aamodt, emeritus professor at Radford University in Virginia, attributes the decline in number of serial killings to less frequent use of parole, improved forensic technology, and people behaving more cautiously. Causes for the general reduction in violent crime following the 1990s include increased incarceration in the United States, the end of the crack epidemic in the United States, and decreased lead exposure in early childhood.
Many serial killers have faced similar problems in their childhood development. Hickey's Trauma Control Model explains how early childhood trauma can set the child up for deviant behavior in adulthood; the child's environment (either their parents or society) is the dominant factor determining whether or not the child's behavior escalates into homicidal activity.
Family, or lack thereof, is the most prominent part of a child's development because it is what the child can identify with on a regular basis. "The serial killer is no different from any other individual who is instigated to seek approval from parents, sexual partners, or others." This need for approval is what influences children to attempt to develop social relationships with their family and peers. "The quality of their attachments to parents and other members of the family is critical to how these children relate to and value other members of society."
Wilson and Seaman (1990) conducted a study on incarcerated serial killers, and what they concluded was the most influential factor that contributed to their homicidal activity. Almost all of the serial killers in the study had experienced some sort of environmental problems during their childhood, such as a broken home caused by divorce, or a lack of a parental figure to discipline the child. Nearly half of the serial killers had experienced some type of physical or sexual abuse, and more of them had experienced emotional neglect. 2b1af7f3a8