Spree, mass and serial killers: What's the difference?

The terms 'spree', 'mass' and 'serial' are often used interchangeably when describing patterns of violence. Experts here at Crime+Investigation know better. Each term represents a distinct form of criminal pathology, with its own horrifying logic.

Why bother to make the distinction? Insight helps us understand the societal, psychological and cultural forces that shape why people kill. And of course, help authorities to catch them. It’s also about finding patterns, catching killers and remembering the victims as more than statistics.

Serial killers: Slow and repetitive

Serial killers are methodical predators, defined by their patience. They kill at least three victims in separate events, often leaving weeks, months or years between their crimes. These signature pauses are known as the 'cooling-off period'.

Ted Bundy is one of the most notorious serial killers of all time and like many other serial killers, concealed his monstrous nature behind a facade of charm and intelligence. During the 1970s he murdered dozens of women. Bundy denied the accusations for more than a decade but eventually confessed before his execution in 1989.

The killer who defended himself: The unique and very public trial of Ted Bundy

Ted Bundy's reign of terror ended in a very public trial when he was found guilty of first-degree murder

Another hallmark of serial killers? Victim preferences. They often target specific profiles, drawn by an internal narrative only they understand. Jack the Ripper had a clear 'type' and preyed on vulnerable sex workers in the slums of London’s East End.

Spree Killers: Violence without pause

If serial killers are defined by control, spree killers embody chaos. Their rampages are impulsive, emotional and fast. There’s no cooling-off period. Instead the violence unfolds over days or sometimes hours, often across multiple locations.

Spree killers rarely plan their attacks with meticulous precision. They’re often reacting to a triggering event, like personal betrayal or anger. Nebraskan teenager Charles Starkweather, who murdered 11 people in a matter of months, is one of America’s most notorious spree killers.

Mass murderers: Architects of spectacle

Mass murderers strike all at once. Their acts are usually premeditated, but unlike serial killings, the violence is concentrated. Murders often occur in a single, explosive act, often with a goal to maximise impact and generate as much media attention as possible.

The Federal Bureau of Investigation (FBI) defines mass murder as a crime where four or more people are killed in a single incident. Guns are often the weapon of choice for incidents like the Columbine High School massacre.

The Columbine massacre: What really happened?

A lot of myths and misinformation about the perpetrators has circulated since the school shooting in 1999.

Stephen Paddock’s 2017 attack in Las Vegas is another shocking case. From his perch in a hotel room, Paddock killed 60 people and injured hundreds more. It’s one of the deadliest mass shootings in modern U.S. history.

Mass shootings are less common in the United Kingdom but do occur. Notable cases include Derrick Bird, who killed 12 people and injured 11 others during a shooting spree in Cumbria in 2010, and the 1996 Dunblane school massacre. British police define mass shootings as firearm-related violence with at least four casualties.

The language of violence: key terminology

Criminologists and psychologists rely on specific terminology to define and understand spree, mass and serial killers.

1. Cooling-off period: The psychological pause between a serial killer’s crimes, often used to distinguish them from spree and mass killers.
2. Victimology: The study of victims to understand why they were targeted. Serial killers often choose based on personal fantasies, while mass murderers may target symbolic groups.
3. Motivations: The reason behind their actions. Serial killers often seek control, sexual gratification or psychological fulfilment. Spree killers are commonly motivated by triggers like rejection or rage while mass murderers are often spurred by ideology or a desire for notoriety.
4. Spatial and temporal factors: Patterns that can be used to distinguish between the three killing styles. Serial killers operate over extended periods and across various locations. Spree killers may attack multiple sites but within a short time. Mass murderers commit their crimes at one location during a single event.
5. Psychopathology: While all categories often involve antisocial personality traits, the nature of these traits varies: serial killers manipulate, spree killers act impulsively and mass murderers meticulously plan.

The human cost

Behind these clinical terms lie countless victims whose lives were irrevocably cut short. Sadly, the stories of killers like Ted Bundy or Stephen Paddock often overshadow the lives they ended. In some ways the notoriety is a grim reflection of society’s fascination with killers over their victims.

The differences between male and female serial killers

Male serial killers are far more inclined to kill strangers, while female serial killers generally murder those they know

Yet as technology advances, the reign of such killers faces unprecedented challenges. DNA databases, digital surveillance and behavioural profiling have made it harder for serial killers to evade capture. Spree killers, driven by their immediacy, are often stopped quickly, while mass murderers face increased scrutiny from law enforcement and the public.

Fascinated by criminal minds? Get exclusive access to articles like this, as well as episodes, clips, competitions, and more with the Crime+Investigation Newsletter! Sign up today!