Mass murder

Mass murder is a violent crime involving the killing of several people. These deaths usually happen at one location. They also tend to occur during a single event or a short period of time. This crime is different from other types of killing. For example, spree killers move between two or more different locations. Serial killers also differ because they kill people over a very long period. Mass murder is defined differently depending on where you live. In the United Kingdom, it means killing four or more people in one act. In the United States, Congress defines it as killing three or more people. This definition requires that there is no "cooling-off period" between the deaths. A cooling-off period is a break in time between individual killings.

Law enforcement agencies use specific terms to categorize these events. The Investigative Assistance for Violent Crimes Act of 2012 was passed in the United States. This law followed the Sandy Hook Elementary School shooting. It helped federal agencies like the Department of Justice work with state police. The law mandated that "mass killing" means three or more killings during one incident. Mass murder can also be classified by the method used. Some events are called mass shootings if guns are used. Others are called mass stabbings if knives are used. These categories help officials organize their investigations and response plans.

Different groups have used mass murder to reach specific goals. Some terrorist organizations use these tactics to achieve political aims. For instance, the group al-Qaeda killed 2,977 people during the September 11 attacks in 2001. In 2004, al-Qaeda also caused 193 deaths during the Madrid train bombings. Other groups have caused large numbers of deaths in different ways. The Islamic State killed 1,095 people at Camp Speicher. In 2014, the Tehrik-i-Taliban killed 156 children and teachers in Peshawar, Pakistan. In 2023, a Hamas-led attack on Israel resulted in 1,163 deaths. These events show how different groups use violence to impact the world.

Religious cults have also been responsible for many mass killings. A cult is a group that follows a specific leader or set of beliefs. Sometimes these groups commit mass murder-suicides. In 1978, 919 people died in Jonestown, Guyana, under Jim Jones and the Peoples Temple. The Order of the Solar Temple caused 74 deaths across Canada, Switzerland, and France between 1994 and 1997. In 1995, the Aum Shinrikyo group killed 14 people in Tokyo, Japan. Another group, the Movement for the Restoration of the Ten Commandments of God, saw 778 deaths in Uganda in 2000. These incidents show the danger of extreme group control.

Sometimes, mass murder is carried out by individuals or governments. Some autocratic regimes, which are governments with total power, have ordered mass murders. This can include genocide or politicide. In the Soviet Union, leader Joseph Stalin ordered the killing of 7,000 Polish prisoners of war. A man named Vasili Blokhin carried out this task. He shot the prisoners over a period of 28 days. This is considered one of the most organized and long mass murders by one person. Individual killers also have different motives. Some seek revenge, while others may want fame or attention. Killers can target family, coworkers, students, or random strangers.

Police officers study these crimes to improve how they protect people. They look at past events to create new safety recommendations. They often analyze the Columbine High School massacre to learn lessons. In that event, Eric Harris and Dylan Klebold killed 14 people. The killers committed suicide before the first SWAT team arrived. Data shows that the average police response time is often longer than the time the killer is active. Because of this, experts suggest that victims and bystanders take active steps. They recommend that people flee, hide, or fight the shooter. Immediate action by police or bystanders has saved lives in many cases.

Classifying these crimes can be difficult for researchers. Some commentators argue that there are too many ways to label these events. An event might be called a school shooting or workplace violence. It might also be called a crime involving an assault rifle. These labels often depend on the person describing the event. The way we categorize these crimes can change over time. In the late 20th century, people began focusing more on the method and location. These categories help people understand the events, but they also reflect different points of view. Even with better classification, the total number of incidents remains a challenge. In 2020, the United States saw a record 600 mass shootings.