Abduction Site[]
The location where a victim is forcibly taken or lured away by the perpetrator. This site is often crucial in forensic investigations as it may contain evidence that helps profile the Unsub or determine the killer's hunting ground.
Angel of Death[]
- Main article: Angels of Death
Also called "Angel of Mercy" or Medical killer, this type of serial killer is usually female and employed as a caretaker. The Angel of Death decides the victim would be better off if they no longer suffered, then uses their knowledge to manufacture the death of the victim.
Anthropophagy (Cannibalism)[]
The act of consuming human flesh. Cannibalism has been a rare but notable behavior among some serial killers, often linked to extreme psychopathy or delusions, and is sometimes used as a form of control or dominance over the victim.
Autoeroticism[]
A form of sexual gratification achieved through self-stimulation, sometimes involving dangerous or fatal acts, such as asphyxiation. This can occasionally be a factor in certain sexually motivated murders.
Baby Farmer[]
- Main article: Baby Farmers
Baby farmers were men and women who offered to help mothers find homes for their newborns in exchange for a fee.
Behavioral Analysis Unit (BAU)[]
A specialized unit within the FBI that assists in profiling serial offenders and violent criminals by analyzing their behavior, patterns, and motivations. BAU agents often consult on cases of serial murder, kidnapping, and terrorism.
Behavioral Evidence[]
Forensic evidence that suggests certain behaviors used to profile an Unsub.
Black Widow[]
- Main article: Black Widows
A serial killer who kills two or more husbands or lovers for insurance policies or sympathy.
Bloodlust[]
An intense desire to kill or cause harm, often associated with the compulsive behavior of some serial killers. This term is frequently used to describe the uncontrollable urges of lust or thrill killers.
Bluebeard[]
- Main article: Bluebeard
The male equivalent of a Black Widow, the Bluebeard is a man who keeps marrying women and then murdering them.
Body Dump Site[]
The location where a killer disposes of their victim’s body after the murder. The choice of a dump site can provide significant clues about the killer's methods and psychological state, as well as their familiarity with the area.
Burke and Hare Syndrome[]
A term used to describe murderers who kill for financial gain, typically by selling the corpses for medical research or other illicit purposes. Named after the infamous 19th-century Scottish murderers William Burke and William Hare.
Catathymic Crisis[]
A psychological state in which an individual experiences overwhelming emotions, typically rage or frustration, that leads to violent outbursts, often culminating in homicide. This crisis can trigger a single murder or serial killings.
CODIS (Combined DNA Index System)[]
Used by the FBI for data/information storage and comparison of DNA profiles.
Comfort Killer[]
A type of serial killer who murders for material or financial gain, such as inheritance, life insurance, or theft. These killers often carefully plan their murders and usually kill people they know.
Cooling-off Period[]
The time interval between serial murders, which distinguishes serial killing from mass murder and spree killing.
Compulsion[]
A strong, usually irresistible urge to perform a particular act, especially one that is irrational and/or contrary to one's will.
Crime Scene Staging[]
The act of deliberately altering a crime scene to mislead investigators or divert suspicion. This may involve changing the position of the body, planting false evidence, or creating a fake motive for the crime.
Criminal Profiling[]
- See: Profiling
The Depravity Scale[]
Aims to establish societal standards of what makes a crime depraved, and to develop a standardized instrument based on specific characteristics of a crime that must be proven in order to merit more severe sentences.
John Doe/Jane Doe[]
John Doe (masculine) and Jane Doe (feminine) are placeholder names that are used in the United States and the United Kingdom when the true name of a person is unknown or is being intentionally concealed.
Diabolical Narcissism[]
A severe form of narcissism marked by a lack of empathy, grandiosity, and manipulative behavior. Diabolical narcissists view others as mere objects to be used and discarded, which may manifest in acts of extreme violence or cruelty.
Disorganized Serial Killers[]
- Main section: Disorganized Serial Killers
A person who commits a crime haphazardly or opportunistically, using weapons found at the scene and often leaving clues. (M.O.s are typically more difficult to discover, and signatures harder to find.)
Enuresis[]
Persistent bedwetting past the age of five.
Fantasy-driven Killer[]
A killer whose murders are motivated by elaborate fantasies that have been cultivated over time. These fantasies often include sexual or violent themes, and the killer attempts to recreate or act out these fantasies in real life.
Forensic Odontology[]
The study of dental evidence in criminal investigations. Bite marks on victims, as well as the examination of a victim's dental records, are often key elements in identifying both perpetrators and victims.
Hedonistic Killer[]
A type of serial killer motivated by the pleasure they derive from the act of killing. This category can include lust killers, thrill killers, and comfort killers.
Holmes Typology[]
- Main section: Serial Killer Types
A classification system for serial killers developed by Ronald M. Holmes and Stephen T. Holmes. Major categories include Power/Control, Hedonistic, Mission-oriented, and Visionary.
Hunting Ground[]
An area where a serial killer repeatedly finds or abducts victims. It may be a specific location such as a park, neighborhood, or street, and analyzing these patterns can help investigators narrow down suspects.
Hunter-Killer Typology[]
A typology that categorizes serial killers who actively search for victims rather than relying on chance encounters. Hunter-killers may stalk their victims in areas familiar to them, often targeting specific types of people.
Imprint Murder[]
A murder that is carried out as part of a delusional or ritualistic belief system, often symbolizing or fulfilling a personal fantasy for the killer. These murders may involve unusual methods or symbolic acts.
Insanity[]
A legal term for a mental disease or defect that if present at the time of a crime absolves the person of responsibility.
LDSK (Long-Distance Serial Killer)[]
Long-Distance Serial Killer, is an offender who shoots their victims in order to create panic and fear; often improperly referred to as a "sniper".
Linkage Blindness[]
The inability of one law enforcement jurisdiction to compare findings and evidence with another, leading many killings to never be connected as being perpetrated by a serial murderer.
Lonely Hearts Killers[]
- Main article: Lonely Hearts Killers
"Lonely Hearts Killers" (or want-ad killers) find their victims by either posting advertisements to or answering advertisements via newspaper classified ads and personal or lonely hearts ads.
Lust Killer[]
A type of hedonistic serial killer who is sexually motivated and derives sexual satisfaction from the act of murder.
M.O. (Modus Operandi)[]
- Main section: Modus Operandi
In criminal profiling, how an Unsub commits a crime. The M.O. of a serial offender changes with the situation and over time.
Mass Murderer[]
- Main article: Mass Murderer
The act of killing a number of people in a single incident or over a short period, involving more than two victims and typically a large number.
The McDonald Triad[]
A set of three behavioral characteristics that are associated with sociopathic behavior. The McDonald Triad consists of animal cruelty, obsessive firesetting, and persistent bedwetting past age five.
Mission-oriented Killer[]
A type of serial killer who believes they are on a mission to rid the world of certain types of people, such as prostitutes or specific ethnic groups.
Murderabilia[]
Memorabilia centered around famous serial killers, includes paintings, writings, and poems by the killers.
Mysopedia[]
Sadistic pedophilia. Albert Fish is one of the classic examples.
NCAVC (National Center for the Analysis of Violent Crime)[]
A component of the FBI's Critical Incident Response Group located at Quantico, Virginia. NCAVC provides behaviorally-based operational support to federal, state, local and international law enforcement agencies involved in the investigation of unusual or repetitive violent crimes, communicated threats, terrorism, and other matters of interest to law enforcement.
Organ Theft[]
A form of crime in which organs are harvested from victims, either while alive or post-mortem, typically for illegal sale or use in transplantation. Though rare, organ theft has appeared in cases involving serial killers or human trafficking networks.
Organized Serial Killers[]
- Main section Organized Serial Killers
A person who commits a planned crime, in a premeditated manner, leaving few to no clues. This type of offender may also carry a "kit" to a potential crime scene, and will generally choose their victims with precise specifications.
Paraphilia[]
Any group of psychosexual disorders characterized by feelings, fantasies, or activities involving non-human objects or non-consenting partners, such as children or pain and humiliation administered to oneself and/or partner, and other sexual deviations.
Pathological Liar[]
A person who compulsively lies, often without clear benefit or reason. Some serial killers are known for being pathological liars, manipulating those around them to evade detection or maintain control over others.
Posing[]
- Main section Posing
When a killer arranges the body of the victim in a certain way to shock the finder or for the killer's own gratification.
Power/Control Killer[]
A type of serial killer who is motivated by the desire to exert power and control over their victims. They often derive pleasure from the victim's suffering.
Profiling[]
The use of observation of a crime scene or scenes and the pattern of crimes to determine investigatively relevant characteristics of the perpetrator that is used as a guide for police and other authorities to narrow down a list of suspects and devise a strategy for questioning.
It's a behavioral and investigative tool that is intended to help investigators to profile unknown criminal subjects or offenders.
Geographic Profiling[]
Using aspects of a geographical relationship among crime scenes and victims to infer offender characteristics.
Psychopathy[]
A personality disorder manifested in people who use a mixture of charm, manipulation, intimidation, and occasionally violence to control others, in order to satisfy their own selfish needs.
Ritualistic Killing[]
A murder that involves specific, repeated actions or symbolism, often stemming from a killer's personal belief system or fantasy. These acts are typically performed in a specific order or manner, giving insight into the psychological state of the killer.
Serial Killer[]
- Main article: Serial Killers
While there are numerous definitions of the term, it generally refers to a person who murders three or more people over more than thirty days, with a "cooling-off" period between each murder, and whose motivation for killing is largely based on psychological gratification. Believed to have been coined in English by FBI Special Agent Robert Ressler in the 1970s. The FBI is increasingly accepting the definition of a serial killer as someone who kills two or more people, with the important differentiator being the cooling-off period.
Serial Killer Cycle[]
- The Aura Phase: The killer begins losing grip on reality.
- The Trolling Phase: The killer searches for a victim.
- The Wooing Phase: The killer lures the victim.
- The Capture Phase: The victim is entrapped.
- The Murder or Totem Phase: The emotional high for the killer.
- The Depression Phase: Occurs after the killing.
Sexual Sadism[]
A condition where an individual derives pleasure from inflicting pain, suffering, or humiliation on others. Sexual sadism is a common trait among sexually motivated serial killers, who may torture their victims as part of the crime.
Shallow Grave[]
A hastily dug grave, often used by killers to conceal their victims' bodies. Shallow graves are typically located in isolated areas, and bodies found in these graves may provide forensic evidence such as decomposition patterns.
Signature[]
- Main section: Signature
In criminal profiling, why an Unsub commits a crime. It serves the emotional or psychological needs of the offender. The signature comes from within the psyche of the offender, and it reflects a deep fantasy need that the killer has for his victims.
"Son of Sam" Laws[]
- Main section "Son of Sam" Laws
Laws existing in some states that prevent murderers from profiting from the publicity generated by their crimes.
Souvenir[]
- See: Trophy
Spree Killer[]
- Main article: Spree Killers
Killings at two or more locations without a cooling-off period between murders, committed by an offender or offenders
Staging[]
- Main section: Staging
When a crime scene is set up to look like one type of crime in order to mislead an investigation and cover up another crime, i.e., when a fire is set to cover up a murder.
Stalker[]
One who follows and observes another persistently, usually out of obsession or derangement.
Stressors[]
The specific incidents that drive an offender over the edge to commit a crime.
Trophy[]
A personal item taken from a victim and kept by the offender in order to be used as a memory aid for the offender to relive the crime.
Typology of Offenders[]
A classification system used to categorize different types of criminals based on their behaviors, motivations, and psychological profiles. In the case of serial killers, typologies often include categories such as organized/disorganized, hedonistic, and power/control.
Unsub[]
Short for "Unknown Subject," this term is used by law enforcement to describe a perpetrator whose identity is unknown at the time of investigation. Though the term is rooted in police terminology, it gained widespread recognition through its frequent use in television shows like Criminal Minds . In real-world law enforcement, the term is not as commonly used, often being replaced by "suspect" or "perpetrator." However, Unsub has become a popular media shorthand for unidentified criminals, especially in cases involving serial killers or other complex investigations where profiling plays a role.
ViCAP (Violent Criminal Apprehension Program)[]
A unit of the United States Federal Bureau of Investigation responsible for the analysis of serial violent and sexual crimes, organizationally situated within the Critical Incident Response Group’s (CIRG) National Center for the Analysis of Violent Crime (NCAVC).
Victimology[]
The study of victims to understand why they were chosen by the serial killer. This can help in profiling the offender.
Visionary Killer[]
A type of serial killer who is compelled to murder because they believe they are being directed by voices or visions, often associated with a mental illness.