Barrio Azteca (2,000 members)
One of America's most violent prison gangs, Barrio Azteca is most active in Texas prisons as well as communities in southwestern Texas and southeastern New Mexico.
Members are often linked to Mexican drug cartels, and the gang's main source of income is the smuggling of heroin, cocaine, and marijuana from Mexico into the U.S. for distribution both inside and outside the prison systems.
The gang has been tied to immigration smuggling, arson, assault, auto theft, burglary, extortion, intimidation, kidnapping, robbery, and weapons violations.
Black Guerrilla Family (100-300 members and thousands of associates)
The Black Guerrilla Family was founded in 1966 in the California prison system by Black Panther George Jackson.
Highly organized with a supreme leader and a central committee, the group operates primarily in the states of California and Maryland promoting an anti-government philosophy.
The gang gets income from distributing cocaine and marijuana obtained from local Mexican drug traffickers, and it's also involved in auto theft, burglary, drive-by shootings, and homicide.
Sources: U.S. Department of Justice and Robert Walker
Dead Man Incorporated (370+ members and thousands of associates)
Three prison inmates created the Dead Man Incorporated in the 1980s in the Maryland Division of Corrections.
One of the three founders, Perry Roark, tried to join the Black Guerrilla Family but was rejected and started his own gang.
In 2006 leadership told a member to begin recruiting in Virginia, so he assaulted a cop to get into the system. Dead Man has started swallowing up smaller gangs and is now one of the largest prison gangs in Maryland.
The gang is involved in murder-for-hire, acts of intimidation, violence, and drug distribution.
Sources: U.S. Department of Justice, Baltimore Sun, and Robert Walker
Ñeta (7,000 members in Puerto Rico and 5,000 in the U.S.)
One of the largest and most violent gangs in America, Ñeta has chapters both inside and outside prisons in 36 cities and within nine states (primarily in the Northeast).
Ñeta's main source of income comes from distributing powdered and crack cocaine, heroin, marijuana, and, to a lesser extent, LSD, ecstasy, meth, and PCP.
Ñeta members also commit crimes including assault, auto theft, burglary, drive-by shooting, extortion, home invasion, money laundering, robbery, weapons, explosives trafficking, and witness intimidation.
Sources: U.S. Department of Justice and Robert Walker
The Hermanos de Pistoleros Latinos (1,000 members)
The Hermanos de Pistoleros Latinos, a Hispanic prison gang with about 1,000 members, was formed near Laredo, Texas, in the 1980s.
HPL also operates in several cities in Mexico, particularly Nuevo Laredo. HPL keeps close ties with Mexican drug cartels and is involved in trafficking large quantities of cocaine and marijuana from Mexico into the U.S. for distribution.
In 2007 members of HPL were charged with stealing large loads of narcotics from McAllen, Texas, drug traffickers and reselling the drugs.
Sources: U.S. Department of Justice, Robert Walker, and Associated Press
Public Enemy Number One (500 members)
Public Enemy Number One (PEN1) is the fastest-growing "white power" prison gang in the U.S., with chapters sprouting up on both coasts and in the South.
The group has amplified its power by forming an alliance with the Aryan Brotherhood and the Nazi Low Riders.
PEN1 members, like a lot of white power groups, push meth. They've also engaged in assault, attempted murder, homicide, auto theft, burglary, and identity theft.
Sources: U.S. Department of Justice and Robert Walker
Mexican Mafia, also known as La Eme (400 members and 1,000+ associates)
Formed in California prisons in the 1950s, the Mexican Mafia has about 400 members who follow strict rules.
Mainly comprised of Mexican-American males who previously belonged to a Southern California street gang, La Eme is a powerful California gang.
Its main source of income is controlling gambling and prostitution within the prison systems, in addition to extorting drug distributors outside prison and distributing meth, cocaine, heroin, and marijuana in prisons and on the streets.
Its members are very closely connected to Mexican cartels.
Sources: U.S. Department of Justice and Robert Walker
Nazi Low Riders (1,000 - 5,000 members)
The Nazi Low Riders (NLR) is a white supremacist gang that operates in prisons and communities around the Pacific and Southwestern regions.
The members, most of whom have a history of street gang activity and drug abuse, move meth as well as smaller amounts of heroin and marijuana.
NLR have also been involved in armed robbery, assault, assault with deadly weapons, murder and attempted murder, identity fraud, money laundering, witness intimidation, and witness retaliation.
Source: U.S. Department of Justice
Mexikanemi, also known as Texas Mexican Mafia (2,000 members)
Also known as the Texas Mexican Mafia, Mexikanemi was formed in the early 1980's in Texas prisons and most members are Mexican nationals or Mexican-American Texans.
Mexikanemi runs a huge drug-trafficking operation involving cocaine, heroin, ecstasy pills, marijuana, and meth in the Southwest, particularly in Texas.
Its members are tight with Mexican cartels, especially the paramilitary group Los Zetas.
Nuestra Familia (250 members and 1,000+ associates)
Nuestra Familia is an extremely violent gang that originated in the California prison system.
Its subordinate Norteños, consisting primarily of Mexican-American gangsters from Central and Northern California, has more than 1,000 members.
The gang gets money from extortion as well as distributing cocaine, heroin, marijuana, and meth in Pacific prison systems as well as in outside communities.
Nuestra Familia is also involved in homicide and robbery.
Source: The U.S. Department of Justice
The Texas Syndicate (1,300 members and 10,000+ associates)
The Texas Syndicate (TS), which has mostly Mexican-American inmates, formed in California’s Folsom prison in the early 1970s in direct response to the Aryan Brotherhood and Mexican Mafia preying on native Texas inmates.
Active on both sides of the U.S.-Mexico border, TS smuggles multi-ton quantities of marijuana and loads of powdered cocaine, heroin, and meth from Mexico into the U.S. for distribution both inside and outside of prison.
Like Mexikanemi, the group is tight with Los Zetas. TS activities include drug trafficking, extortion, prostitution, protection, illegal gambling, and contract killing.
Released or paroled members surrender a 10 percent tax (“the dime”) of all money generated outside to the gang on the inside.
Source: U.S. Department of Justice and Robert Walker
The Aryan Brotherhood (20,000 members)
The Aryan Brotherhood (AB) is notoriously violent and has about 20,000 members in and out of prison. The group has an alliance with La Eme since the two are mutual enemies of Black Guerrilla Family.
AB is primarily active in the Southwestern and Pacific regions of the U.S., but its reach is expansive — the FBI estimates that while the gang makes up less than 1 percent of the prison population, it is responsible for up to 18 percent of murders in the federal prison system.
The gang's income comes distributing cocaine, heroin, marijuana, and methamphetamine within the prison systems and on the street.
The gang is not to be confused with the Texas Aryan Brotherhood, which is a separate group founded by Texas prisoners who were denied admission into the AB.
Sources: Southern Poverty Law Center and U.S. Department of Justice