A copycat suicide is defined as an emulation of another suicide that the person attempting suicide knows about either from local knowledge or due to accounts or depictions of the original suicide on television and in other media. The publicized suicide serves as a trigger, in the absence of protective factors, for the next suicide by a susceptible or suggestible person. This is referred to as suicide contagion.
A school shooting is an armed attack at an educational institution, such as a primary school, secondary school, high school or university, involving the use of a firearm. Many school shootings are also categorized as mass shootings due to multiple casualties. The phenomenon is most widespread in the United States, which has the highest number of school-related shootings, although school shootings have taken place elsewhere in the world.
Mass murder is the violent crime of killing a number of people, typically simultaneously or over a relatively short period of time and in close geographic proximity. A mass murder typically occurs in a single location where one or more persons kill several others.
A spree killer is someone who commits a criminal act that involves two or more murders in a short time, often in multiple locations. There are different opinions about what durations of time a killing spree may take place in. The United States Bureau of Justice Statistics has spoken of "almost no time break between murders", but some academics consider that a killing spree may last weeks or months, e.g. the case of Andrew Cunanan, who murdered five people over three months.
Crime in Canada is generally considered low overall. Under the Canadian constitution, the power to establish criminal law and rules of investigation is vested in the federal Parliament. The provinces share responsibility for law enforcement, and while the power to prosecute criminal offences is assigned to the federal government, responsibility for prosecutions is delegated to the provinces for most types of criminal offences. Laws and sentencing guidelines are uniform throughout the country, but provinces vary in their level of enforcement.
In the United States, the relationship between race and crime has been a topic of public controversy and scholarly debate for more than a century. Crime rates vary significantly between racial groups; however, academic research indicates that the over-representation of some racial minorities in the criminal justice system can in part be explained by socioeconomic factors, such as poverty, exposure to poor neighborhoods, poor access to public and early education, and exposure to harmful chemicals and pollution. Racial housing segregation has also been linked to racial disparities in crime rates, as black Americans have historically and to the present been prevented from moving into prosperous low-crime areas through actions of the government and private actors. Various explanations within criminology have been proposed for racial disparities in crime rates, including conflict theory, strain theory, general strain theory, social disorganization theory, macrostructural opportunity theory, social control theory, and subcultural theory.
An active shooter is the perpetrator of an ongoing mass shooting. The term is primarily used to characterize shooters who are targeting victims indiscriminately and at a large scale, who oftentimes, will either commit suicide or intend to be killed by police. More generally, an active perpetrator of a mass murder may be referred to as an active killer.
Crime has been recorded in the United States since its founding and has fluctuated significantly over time. Most available data underestimate crime before the 1930s, giving the false impression that crime was low in the early 1900s and had a sharp rise after. Instead, violent crime during the colonial period was likely three times higher than the highest modern rates in the data we have, and crime had been on the decline since colonial times. Within the better data for crime reporting and recording available starting in the 1930s, crime reached its broad, bulging modern peak between the 1970s and early 1990s. After 1992, crime rates have generally trended downwards each year, with the exceptions of a slight increase in property crimes in 2001 and increases in violent crimes in 2005–2006, 2014–2016 and 2020–2021.
Gun violence is a term of political, economic and sociological interest referring to the tens of thousands of annual firearms-related deaths and injuries occurring in the United States. In 2022, up to 100 daily fatalities and hundreds of daily injuries were attributable to gun violence in the United States. In 2018, the most recent year for which data are available, the Centers for Disease Control and Prevention's (CDC) National Center for Health Statistics reported 38,390 deaths by firearm, of which 24,432 were suicides. The national rate of firearm deaths rose from 10.3 people for every 100,000 in 1999 to 11.9 people per 100,000 in 2018, equating to over 109 daily deaths. In 2010, there were 19,392 firearm-related suicides, and 11,078 firearm-related homicides in the U.S. In 2010, 358 murders were reported involving a rifle while 6,009 were reported involving a handgun; another 1,939 were reported with an unspecified type of firearm. In 2011, a total of 478,400 fatal and nonfatal violent crimes were committed with a firearm.
Gun-related violence is violence committed with the use of a firearm. Gun-related violence may or may not be considered criminal. Criminal violence includes homicide, assault with a deadly weapon, and suicide, or attempted suicide, depending on jurisdiction. Non-criminal violence includes accidental or unintentional injury and death. Also generally included in gun violence statistics are military or para-military activities.
A copycat crime is a criminal act that is modeled after or inspired by a previous crime. It notably occurs after exposure to media content depicting said crimes, and/or a live criminal model.
A mass shooting is a violent crime in which one or more attackers kill or injure multiple individuals simultaneously using a firearm. There is no widely accepted definition of "mass shooting", and different organizations tracking such incidents use different criteria. Mass shootings are often characterized by the indiscriminate targeting of victims in a non-combat setting, and thus the term generally excludes gang violence, shootouts and warfare. Mass shootings may be done for personal and psychological reasons, but have also been used as a terrorist tactic. The perpetrator of an ongoing mass shooting may be referred to as an active shooter.
Crime contagion models relate to the idea, of whether crime is contagious. Contagion models predict a positive relationship between neighborhood violent crime rates and the propensity of moving to opportunity (MTO) participants to engage in violent crime. The notion of crime spreading across surrounding environments feeds on the idea of clinical hysteria. Hysteria and the fear of crime are the main components of the contagion model.
The Public Safety and Recreational Firearms Use Protection Act, popularly known as the Federal Assault Weapons Ban, was a subsection of the Violent Crime Control and Law Enforcement Act of 1994, a United States federal law which included a prohibition on the manufacture for civilian use of certain semi-automatic firearms that were defined as assault weapons as well as certain ammunition magazines that were defined as large capacity.
Racial biases are a form of implicit bias, which refers to the attitudes or stereotypes that affect an individual's understanding, actions, and decisions in an unconscious manner. These biases, which encompass unfavorable assessments, are often activated involuntarily and without the awareness or intentional control of the individual. Residing deep in the subconscious, these biases are different from known biases that individuals may choose to conceal for the purposes of social and/or political correctness. Police officers have implicit bias, regardless of their ethnicity. Racial bias in criminal news reporting in the United States is a manifestation of this bias.
The Ferguson effect is an increase in violent crime rates in a community caused by reduced proactive policing due to the community's distrust and hostility towards police. The Ferguson effect was first proposed after police saw an increase in violence following the 2014 shooting of Michael Brown in Ferguson, Missouri. The term was coined by Doyle Sam Dotson III, the chief of the St. Louis police, to account for an increased murder rate in some U.S. cities following the Ferguson unrest. Whether the Ferguson effect really exists is subject of discussions with many published studies reporting contradicting findings concerning whether there is a change in crime rates, number of 911 calls, homicides, and proactive policing. Furthermore, the effect and influence of the portrayal of police brutality in the media is also contested.
Mass shootings are incidents involving multiple victims of firearm related violence. Definitions vary, with no single, broadly accepted definition. One definition is an act of public firearm violence—excluding gang killings, domestic violence, or terrorist acts sponsored by an organization—in which a shooter kills at least four victims. Using this definition, a 2016 study found that nearly one-third of the world's public mass shootings between 1966 and 2012 occurred in the United States, In 2017 The New York Times recorded the same total of mass shootings for that span of years. A 2023 report published in JAMA covering 2014 to 2022, found there had been 4,011 mass shootings in the US, most frequent around the southeastern U.S. and Illinois. This was true for mass shootings that were crime-violence, social-violence, and domestic violence-related. The highest rate was found in the District of Columbia, followed by Louisiana and Illinois.
A mass stabbing is a single incident in which multiple victims are injured or killed with a sharp object thrusted at the victims, piercing through the skin and injuring the victims. Examples of sharp instruments used in mass stabbings may include kitchen knives, utility knives, sheath knives, scissors, katanas, hammers, screwdrivers, icepicks, bayonets, axes, machetes and glass bottles. Knife crime poses security threats to many countries around the world.
The Columbine effect is the legacy and impact of the Columbine High School massacre, which occurred on April 20, 1999, at Columbine High School in Columbine, Colorado. The shooting has had an effect on school safety, policing tactics, prevention methods, and inspired numerous copycat crimes, with many killers taking their inspiration from Eric Harris and Dylan Klebold by describing the two perpetrators as being martyrs or heroes.
Investigative Assistance for Violent Crimes Act of 2012 (IAVCA) is a federal law in the United States that clarifies the statutory authority for federal law enforcement agencies to provide investigatory assistance to the States. The Act provided that, upon request from a state or local government, federal law enforcement may assist in the investigation of violent crime occurring in non-federal, public places. The Act did not create any new crimes but rather mandated a definition, across federal law enforcement agencies, of "mass killings" as a killing of three or more victims in the same incident. The Act enabled the Federal Bureau of Investigation to develop a program of research and training to address active shooter incidents.
