serial murder
A criminological term describing multiple murders committed by the same offender over an extended period, typically with cooling-off periods between incidents. Not a distinct legal offense in most jurisdictions.

Definition
Serial murder refers to the killing of multiple victims in separate incidents over a period of time, typically with emotional cooling-off periods between each homicide. While widely used in criminology, forensic psychology, and media coverage, "serial murder" is not a separately defined criminal offense in most legal systems, including U.S. federal law.
The FBI's Behavioral Analysis Unit defines serial murder as the unlawful killing of two or more victims by the same offender(s) in separate events. This criminological definition helps law enforcement identify patterns and investigate related homicides, but it does not create a distinct legal charge. Each homicide committed by a serial killer is prosecuted individually under applicable murder statutes.
In U.S. federal jurisdiction, murders are prosecuted under general homicide provisions such as 18 U.S.C. § 1111, which defines murder as the unlawful killing of a human being with malice aforethought. Federal jurisdiction applies when murders occur on federal property, involve federal officials, cross state lines in certain circumstances, or otherwise fall within federal competence. The serial nature of the crimes may influence sentencing considerations and prosecutorial strategy, but does not change the fundamental legal classification of each individual homicide.
When multiple murders are prosecuted together, they are typically charged as separate counts of murder or first-degree murder under the relevant jurisdiction's statutes. Aggravating factors such as premeditation, torture, or multiple victims may enhance sentencing, potentially including capital punishment in jurisdictions where it remains available. The pattern of serial killing may be presented as evidence of premeditation, planning, or the defendant's ongoing danger to society.
Related entries
Related articles

I Survived a Serial Killer
A&E documentary series where real survivors share first-person accounts of escaping serial killers including the Railway Killer, the Toy Box Killer, and the Craigslist Killer.

The Fox Hollow Murders: Playground of a Serial Killer
A four-part ABC News Studios docuseries about Herbert Baumeister, an Indiana businessman who murdered gay men in the 1990s and buried their remains at Fox Hollow Farm.

Unknown Serial Killers of America
Unknown Serial Killers of America is an Oxygen/Hayu anthology docuseries premiering May 18, 2025, profiling six lesser-known American serial killers across six episodes.

Crime Scene: The Times Square Killer
Netflix docuseries about Richard Cottingham, the 'Torso Killer' who murdered women across New York and New Jersey from 1967 to 1980, directed by Joe Berlinger.

Jack the Ripper: Conspiracies
Jack the Ripper: Conspiracies is a 2002 documentary film covering the unsolved 1888 Whitechapel serial murders in London, available on Apple TV and Prime Video.

H.H. Holmes: America's First Serial Killer
A 2004 documentary by John Borowski covering the crimes of H.H. Holmes, the fraudster and serial killer who built a 'Murder Castle' near the 1893 Chicago World's Fair.

Baraja: la firma del asesino
Baraja: la firma del asesino is a Netflix documentary series about Alfredo Galán Sotillo, an ex-soldier who murdered six people near Madrid in 2003, leaving playing cards at crime scenes as his signature.

Conversations with a Killer: The Son of Sam Tapes
Netflix docuseries about David Berkowitz, the "Son of Sam" serial killer who murdered and attacked victims across NYC in 1976–1977, featuring previously unheard 1980 prison recordings.

The Most Dangerous Animal of All
The Most Dangerous Animal of All is a Disney+ documentary series about the unsolved Zodiac Killer murders, following Gary L. Stewart's claim that his biological father was the killer.

Conversations with a Killer: The Jeffrey Dahmer Tapes
Netflix docuseries built around audio recordings of Jeffrey Dahmer, the Milwaukee serial killer who murdered and dismembered 17 boys and men between 1978 and 1991.

Captive Audience: A Real American Horror Story
Captive Audience is a Disney+/Hulu docuseries about the 1972 kidnapping of 7-year-old Steven Stayner and the 1999 Yosemite murders committed by his brother Cary Stayner.

L'Affaire Fourniret: Dans la tête de Monique Olivier
Netflix documentary series about the Fourniret-Olivier serial murder case in France and Belgium, re-examining Monique Olivier's role in at least seven killings between 1987 and 2003.