Serial killer

A serial killer is typically a person who murders three or more people, usually in service of abnormal psychological gratification, 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 killings involve sexual contact with the victim, but the Federal Bureau of Investigation (FBI) states that the motives of serial killers can include anger, thrill-seeking, financial gain, and attention seeking. The murders may be attempted or completed in a similar fashion. 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 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 number of active serial killers in the country peaked in 1989 and has been steadily trending downward since. The cause of this spike in serial killings has been attributed to urbanization, which put people in close proximity and offered anonymity. 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.

Some commonly found characteristics of serial killers include the following:

• They may exhibit varying degrees of mental illness or psychopathy, which may contribute to their homicidal behavior.

• For example, someone who is mentally ill may have psychotic breaks that cause them to believe they are another person or are compelled to murder by other entities.

• Psychopathic behavior that is consistent with traits common to some serial killers include sensation seeking, a lack of remorse or guilt, impulsivity, the need for control, and predatory behavior. Psychopaths can seem 'normal' and often quite charming, a state of adaptation that psychiatrist Hervey Cleckley called the "mask of sanity".

• They were often abused—emotionally, physically, or sexually—by a family member.

• Serial killers may be more likely to engage in fetishism, partialism or necrophilia, which are paraphilias that involve a strong tendency to experience the object of erotic interest almost as if it were a physical representation of the symbolized body. Individuals engage in paraphilias which are organized along a continuum; participating in varying levels of fantasy perhaps by focusing on body parts (partialism), symbolic objects which serve as physical extensions of the body (fetishism), or the anatomical physicality of the human body; specifically regarding its inner parts and sexual organs (one example being necrophilia).

• A disproportionate number exhibit one, two, or all three of the Macdonald triad of predictors of future violent behavior:

• Many are fascinated with fire setting.

• They are involved in sadistic activity; especially in children who have not reached sexual maturity, this activity may take the form of torturing animals.

• More than 60 percent, or simply a large proportion, wet their beds beyond the age of 12.

• They were frequently bullied or socially isolated as children. For example, Henry Lee Lucas was ridiculed as a child and later cited the mass rejection by his peers as a cause for his hatred of everyone. Kenneth Bianchi was teased as a child because he urinated in his pants, suffered twitching, and as a teenager was ignored by his peers.

• Some were involved in petty crimes, such as fraud, theft, vandalism, or similar offenses.

• Often, they have trouble staying employed and tend to work in menial jobs. The FBI, however, states, "Serial murderers often seem normal; have families and/or a steady job." Other sources state they often come from unstable families.

• Studies have suggested that serial killers generally have an average or low-average IQ, although they are often described, and perceived, as possessing IQs in the above-average range. A sample of 202 IQs of serial killers had a median IQ of 89.