Reports on the number of people involved in criminal gangs, by locale.
There were at least 30,000 gangs and 800,000 gang members active across the USA in 2007. About 900,000 gang members lived "within local communities across the country," and about 147,000 were in U.S. prisons or jails in 2009. By 1999, Hispanics accounted for 47% of all gang members, Blacks 31%, Whites 13%, and Asians 6%.
The Latin Kings have organized chapters in over 41 US states, most notably Illinois, and several Latin American and European countries, including: Mexico, Spain, Dominican Republic, Canada, Italy, Ecuador, Peru, Puerto Rico, Portugal, Brazil, United Kingdom and others.
The Chicago Crime Commission publication "The Gang Book 2012" gave the statistic that Chicago has more gang members than any other city in the United States: 150,000. The city had 532 murders in 2012, however, it saw a decrease to 413 murders in 2013. Not all murders are gang-related, but the Chicago Police Department states that 80% of all shootings and murders in the city are gang-related, which means that most violence in the city is gang upon gang violence.
Los Angeles has held the nickname "gang capital of America" since 1930 because approximately 120,000 gang members reside in the city, and tens of thousands more in surrounding Los Angeles County.
Hong Kong's Triads include up to 160,000 members in the 21st century. It was estimated that in the 1950s, there were 300,000 Triad members in Hong Kong. The Chinese government claims that police have eliminated 1,221 triad-style gangs across China since a crackdown was launched in 2006. More than 87,300 suspects have been arrested.
- List of gangs in the United States
- Gangs in Australia
- Gangs in Canada
- Gangs in the United Kingdom
- Gangs in New Zealand
- COPS Office: Gangs
- L.A. Gangs: Nine Miles and Spreading. Laweekly.com. December 13, 2007.
- Report: Gang yo what up membership on the rise across U.S., by Kevin Johnson, USA Today, January 30, 2009
- Into the Abyss: The Racial and Ethnic Composition of Gangs
- Karen L. Kinnear. Gangs: a reference handbook. ABC-CLIO.
-  Archived November 29, 2011, at the Wayback Machine.
- Gang mayhem grips LA, The Observer, March 18, 2007
- El Salvador's teenage beauty queens live and die by gang law, The Observer, November 10, 2002
- 100,000 foot soldiers in Mexican cartels, Washington Times, March 3, 2009.
- Criminal Investigation: Fight Against Organized Crime (1), Overview of Japanese Police, National Police Agency (June 2007).
- Asian Triads Archived February 17, 2013, at the Wayback Machine.
- Hong Kong's T-Shirt Contest. TIME. November 28, 2007.
- Police chief and businessmen arrested in triad crackdown. Times Online. August 14, 2009.
- Italian Organized Crime—Overview Archived October 7, 2010, at the Wayback Machine.. FBI.gov.
- Frederick Thrasher, The Gang: A Study of 1,313 Gangs in Chicago, Chicago: University of Chicago Press, 1927 ASIN: B000IZWOBA
- Varrio Warfare: Violence in the Latino Community, Gabriel C. Morales, 1998 ASIN: B0018HRNHM
- Roberson, Cliff. "Exploring Juvenile Justice", California: Wadsworth/Thompson Learning, 2000 ISBN 978-1-928916-09-3
- Daniels, Peggy. ed. "Gangs", Michigan: The Gale Group, 2008