There is no universally agreed-upon definition of "gang" in the United States. Gang, youth gang and street gang are terms widely and often interchangeably used in mainstream coverage. Reference to gangs often implies youth gangs. In some cases, youth gangs are distinguished from other types of gangs; how youth is defined may vary as well.
Motorcycle gangs, prison gangs, hate groups, adult organized crime groups, terrorist organizations and other types of security threat groups are frequently but not always treated separately from gangs in both practice and research.
Federal definition. The federal definition of gang as used by the Department of Justice and the Department of Homeland Security's Immigration and Customs Enforcement (ICE), is :
- An association of three or more individuals;
- Whose members collectively identify themselves by adopting a group identity, which they use to create an atmosphere of fear or intimidation, frequently by employing one or more of the following: a common name, slogan, identifying sign, symbol, tattoo or other physical marking, style or color of clothing, hairstyle, hand sign or graffiti;
- Whose purpose in part is to engage in criminal activity and which uses violence or intimidation to further its criminal objectives.
- Whose members engage in criminal activity or acts of juvenile delinquency that if committed by an adult would be crimes with the intent to enhance or preserve the association's power, reputation or economic resources.
- The association may also possess some of the following characteristics:
- The members may employ rules for joining and operating within the association.
- The members may meet on a recurring basis.
- The association may provide physical protection of its members from others.
- The association may seek to exercise control over a particular geographic location or region, or it may simply defend its perceived interests against rivals.
- The association may have an identifiable structure.
Both the Department of Justice and ICE have distinct definitions for transnational organized crime and gangs. The federal definition of gangs excludes drug trafficking organizations, terrorist organizations, traditional organized crime groups, such as La Cosa Nostra, and groups that fall within the Department of Justice's definition of transnational organized crime.
State definition. A number of states use the following definition of gang, often with minor modifications (this definition was originally devised by the California legislature):
"criminal street gang' means any ongoing organization, association or group of three or more persons, whether formal or informal, having as one of its primary activities the commission of one or more of the criminal acts [...], having a common name or common identifying sign or symbol, and whose members individually or collectively engage in or have engaged in a pattern of criminal gang activity."
Defining "youth gangs"
The National Gang Center (which is cosponsored by the Bureau of Justice Assistance and the Office of Juvenile Justice and Delinquency Prevention) conducts the National Youth Gang Survey. The survey reports solely on youth gangs, which the National Gang Center describes as "a group of youths or young adults [the responding agency is] willing to identify as a 'gang.'"
When they report to the National Youth Gang Survey, law enforcement agencies indicate that group criminality is of greatest importance in how they define a gang. The presence of leadership is of least importance.
Much of the research literature about gangs focuses primarily on youth gangs, as opposed to adult gangs. Researchers accept the following criteria for classifying groups as gangs:
- The group has three or more members, generally aged 12-24.
- Members share an identity, typically linked to a name, and often other symbols.
- Members view themselves as a gang, and they are recognized by others as a gang.
- The group has some permanence and a degree of organization.
- The group is involved in an elevated level of criminal activity.
Defining "types" of gangs
The National Gang Intelligence Center and the National Drug Intelligence Center collaborated to produce the National Gang Threat Assessment in 2009. The book discusses street gangs, prison gangs and outlaw motorcycle gangs. Each gang type merits its own definition and discussion of the characteristics that differ at national, regional and local levels.
Defining "gang member" and "gang crime"
Localities interested in pursuing anti-gang policies, strategies and programs face the challenge of developing operational definitions for the terms "gang," "gang member" and "gang crime" (or "gang-related offense"). Many criminal justice policymakers and practitioners operate under practical definitions unique to their locality and its explicit gang-related challenges.
Some localities fail to address the need for definition or to consider elements of definitions already in use. Failing to define the terms "gang" and "gang crime" as the terms are commonly used in a community undermines the community's ability to reliably measure progress and outcomes related to gangs and gang activity.
California and other states and localities have instituted various criteria and threshold levels an individual must meet to be classified as a gang member. Multiple criteria may need to be documented. For example, 1) a reliable source must identify the person as a gang member, and 2) the person must display gang symbols or use hand signs and display gang tattoos.
[note 2] California Street Terrorism Enforcement and Prevention Act. California Penal Code, section 186.22(f).
[note 3] National Gang Center, National Youth Gang Survey Analysis. Retrieved December 2, 2010, from http://www.nationalgangcenter.gov/Survey-Analysis/Methodology.
[note 4] National Gang Center, National Youth Gang Survey Analysis. Retrieved December 2, 2010, from http://www.nationalgangcenter.gov/Survey-Analysis.
[note 5] This list adapted from National Gang Center, What is a gang?. Retrieved December 2, 2010, from http://www.nationalgangcenter.gov/About/FAQ#q1.
[note 6] Tita, George, and Andrew Papachristos, "The Evolution of Gang Policy: Balancing Suppression and Intervention," in Robert Chaskin, ed., Youth Gangs and Community Intervention: Research, Practice, and Evidence, New York: Columbia University Press, 2009