10 Notorious Prison Gangs That Became Criminal Empires

Prisons have long served as breeding grounds for organized crime. In an environment where survival often depends on alliances, gangs provide protection, identity, access to contraband, and connections that frequently extend far beyond prison walls. What begins as a small group formed for mutual defense can evolve into a sophisticated criminal enterprise with influence reaching into neighborhoods, cities, and even other countries.

Some prison gangs remain confined largely to correctional facilities, while others have grown into powerful organizations involved in drug trafficking, extortion, murder, and organized crime on a massive scale. These ten groups illustrate how prison-born alliances have, in many cases, developed into criminal networks whose influence extends far beyond the cells where they first took shape.

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10 Dead Man Incorporated (DMI)

Dead Man Incorporated, better known as DMI, was founded in 2000 by three inmates within the Maryland Division of Corrections. Originally organized as a white supremacist prison gang, the group gradually shifted toward a more profit-driven criminal enterprise, expanding its membership and forging alliances with organizations including the Black Guerilla Family.

Authorities have linked DMI to a wide range of criminal activities both inside and outside prison, including murder-for-hire schemes, drug trafficking, extortion, assaults, and witness intimidation. Investigations have shown that members often coordinated crimes beyond prison walls using contraband cell phones and outside associates.

Although DMI remains most influential within Maryland’s correctional system, federal prosecutions have identified members operating in several other states. Its evolution from an ideologically driven prison gang into a broader criminal organization illustrates how prison-based groups can expand well beyond their original purpose.^[1]

9 Public Enemy Number 1 (PENI)

Public Enemy Number 1, commonly known as PENI, emerged in California during the mid-1980s as a white supremacist prison gang formed to protect white inmates from rival groups. Over time, it evolved into a prison-and-street gang with members operating both inside correctional facilities and in surrounding communities.

Law enforcement agencies have linked PENI members to drug trafficking, extortion, assaults, and homicide. The gang uses distinctive tattoos, symbols, and coded imagery to identify members and has developed relationships with larger white supremacist organizations, including the Aryan Brotherhood.

Although its membership estimates vary, authorities continue to regard PENI as one of California’s more significant white supremacist prison gangs. Its continued expansion beyond prison walls demonstrates how correctional institutions can serve as launching points for broader criminal organizations.^[2]

8 Brödraskapet

Brödraskapet—Swedish for “The Brotherhood”—was founded inside Sweden’s Kumla Maximum Security Prison on May 27, 1995. The gang developed connections with members of outlaw motorcycle clubs and organized crime, eventually becoming one of Scandinavia’s most prominent prison-based criminal organizations.

Authorities have linked the group to crimes including murder, extortion, drug trafficking, weapons smuggling, and organized violence. Its influence gradually spread beyond prison walls through relationships with criminal organizations operating across Sweden and neighboring countries.

Despite repeated law enforcement crackdowns and the imprisonment of senior members, Brödraskapet remains active within Sweden’s correctional system. Its growth illustrates how prison gangs can become influential players within broader organized crime networks.^[3]

7 Barrio Azteca

Barrio Azteca originated in the Texas prison system during the 1980s before expanding into one of the most influential prison gangs operating along the U.S.-Mexico border. What began as a prison-based organization eventually developed close ties with the Juárez Cartel, dramatically increasing both its reach and its criminal influence.

Authorities have connected Barrio Azteca to drug trafficking, racketeering, extortion, money laundering, contract killings, and cross-border organized crime. The gang has played a significant role in violent conflicts surrounding Ciudad Juárez, where it served for years as an enforcement arm for the cartel.

Although its membership extends into prisons across several U.S. states, Barrio Azteca’s influence has been shaped largely by its close relationship with transnational organized crime. That evolution distinguishes it from many prison gangs whose activities remain largely confined to correctional institutions.^[4]

6 The Number Gang

The Number Gang is among the oldest and most influential prison organizations in the world. Its origins stretch back to South Africa during the late nineteenth century, where legends surrounding the outlaw Nongoloza Mathebula became intertwined with prison culture. Over time, those traditions evolved into the prison brotherhoods known today as the 26s, 27s, and 28s.

Each division developed a distinct role within the gang’s internal hierarchy. The 26s traditionally focused on acquiring wealth, the 27s enforced discipline and gang law, and the 28s became associated with military organization and protection. Together, they established an elaborate code of conduct, rituals, symbols, and traditions that continue to influence South African prisons.

Although the Number Gang’s mythology is rooted in prison history, its influence eventually spread into the country’s broader criminal underworld through drug trafficking, extortion, and organized violence. More than a century after its origins, it remains one of South Africa’s most enduring and extensively studied prison gangs.^[5]

5 Trinitarios

The Trinitarios originated among incarcerated Dominican inmates at New York City’s Rikers Island during the late 1980s. Founded by Leonides Sierra and Julio Marine, the gang initially focused on protecting Dominican prisoners from rival groups before expanding into a broader criminal organization operating throughout the northeastern United States.

Over the following decades, Trinitarios established a strong presence in New York, New Jersey, Massachusetts, and other East Coast states, while also developing cells in Spain. Federal prosecutors have linked members to drug trafficking, racketeering, money laundering, murder, and violent assaults, with leadership often coordinating activities both inside and outside correctional facilities.

Although numerous leaders have been arrested and prosecuted, Trinitarios remains active today. Its growth from a prison protection group into a transnational criminal enterprise illustrates how prison-based organizations can extend their influence well beyond the correctional system.^[6]

4 European Kindred

European Kindred, commonly known as EK, was founded in 1998 by inmates at Oregon’s Snake River Correctional Institution. Organized as a white supremacist prison gang, it sought to protect and advance the interests of white inmates while establishing influence within Oregon’s correctional system.

Authorities have connected EK members to drug trafficking, assaults, extortion, robbery, and homicide, while the gang has expanded beyond prison walls into communities across Oregon and neighboring western states. Members typically identify themselves through distinctive tattoos and symbols incorporating the initials “EK.”

Although smaller than some of the national prison gangs on this list, European Kindred has maintained a significant presence in the Pacific Northwest. Its continued influence demonstrates how regional prison gangs can develop into organized criminal networks with operations extending well beyond correctional facilities.^[7]

3 Mexikanemi

Mexikanemi—often called the Texas Mexican Mafia—was established within the Texas Department of Criminal Justice during the early 1980s. Despite the similarity in name, it is distinct from the original Mexican Mafia, or La Eme, which originated in California’s prison system. The two organizations developed independently and have maintained separate leadership structures.

Initially formed to protect Mexican-American inmates from rival prison gangs, Mexikanemi soon expanded into a sophisticated criminal enterprise. Law enforcement agencies have linked the organization to drug trafficking, extortion, arson, murder, and weapons offenses, with members operating both inside correctional facilities and on the streets.

Federal authorities consider Mexikanemi one of the most influential prison gangs in Texas, and investigations have documented connections between its members and Mexican organized crime groups. Its evolution reflects the growing ability of prison gangs to coordinate criminal activity far beyond prison walls.^[8]

2 Neta

Neta was founded during the 1970s inside Puerto Rico’s Oso Blanco maximum-security prison, where it emerged as a prison organization advocating for inmate solidarity and protection. Although its early leadership promoted improving prison conditions, the gang gradually evolved into a major criminal organization with members operating throughout Puerto Rico and parts of the mainland United States.

Authorities estimate that Neta has several thousand members spread across multiple states, particularly in the Northeast. Members have been linked to drug trafficking, robbery, extortion, assault, witness intimidation, and other organized criminal activity, while the gang continues to maintain a significant presence within Puerto Rico’s correctional system.

Unlike many American prison gangs, Neta functions differently depending on location. In Puerto Rico, membership traditionally ends upon an inmate’s release, while mainland chapters have operated more like conventional street gangs. That unusual structure has made Neta one of the more distinctive prison organizations in the Americas.^[9]

1 Aryan Brotherhood

Founded in 1964 at California’s San Quentin State Prison, the Aryan Brotherhood is one of the most infamous prison gangs in American history. The organization emerged during a period of prison desegregation, when white inmates formed racially aligned groups for protection and control. Over time, it developed into a highly organized criminal enterprise with influence extending throughout California and the federal prison system.

Despite having a relatively small membership compared with many street gangs, the Aryan Brotherhood has long exercised influence far beyond its numbers. Federal investigators have linked the organization to drug trafficking, extortion, contract killings, and other organized criminal activities carried out both inside and outside prison. Membership is widely regarded as lifelong, with former inmates often remaining connected to the organization after release.

The gang is also known for its elaborate symbols, including shamrocks, the initials “AB,” swastikas, and the number 666. Decades after its founding, the Aryan Brotherhood remains one of the most closely monitored prison gangs in the United States because of its organizational discipline, violent reputation, and enduring influence within correctional institutions.^[10]