The United Self-Defense Forces of Colombia (Autodefensas Unidas de Colombia – AUC) was a coalition of right-wing death squads that used the conflict to camouflage their illicit economic activities. These included drug trafficking, displacement, kidnapping, and extortion. The AUC once operated in two-thirds of the country with approximately 30,000 soldiers.


The origins of the paramilitaries go back to the early 1980s, when drug traffickers, facing a wave of kidnappings by leftist guerrilla groups, decided to create a death squad they called Death to Kidnappers (Muerte a Secuestradores – MAS). This illegal group assassinated not just the kidnappers, but also any supposed member of the rebels’ infrastructure, which included many innocent civilians, activists, union leaders and politicians. Later, “self-defense” groups emerged, some of them initiated by Colombian army officers and politicians who called for the population to organize in their own defense. Many of them were legally constituted. However, rather than protect civilians from the transgressions of the guerrillas, many of the groups simply worked for drug traffickers, at the behest of large landholders, or both. The alliance with these powerful economic interests gave paramilitary groups access to weapons, cars and communications equipment, but it distorted their original purpose.

Indeed, the rise of the drug traffickers’ economic power would change the face of the conflict. Powerful members of the Medellin Cartel invested heavily in land and, using the paramilitary groups, sought to shield themselves from the guerrillas’ extortion and kidnapping attempts. MAS expanded exponentially in these rural areas. But soon the “self-defense” groups were protecting drug stashes and cargoes rather than civilians. These organizations also unleashed waves of violence against sectors of the population who were considered supporters of the guerrillas. Thousands of civilians were killed, including state agents and politicians, leading the government to criminalize the paramilitary groups.

AUC Factbox


Approximately 30,000 soldiers

The Castaño brothers Fidel, Carlos and Vicente were the founding fathers of Colombia’s paramilitary movement

Criminal Activities
Drug trafficking, kidnapping, extortion, forced displacement

Colombia Factbox

Homicide rate

Criminal Activities
Drug production, kidnapping, domestic drug sales, arms trafficking, money laundering, human trafficking

Principal Criminal Groups
Revolutionary Armed Forces of Colombia (FARC), National Liberation Army (ELN), Urabeños, Rastrojos, Popular Revolutionary Anti-Terrorist Army of Colombia (ERPAC), Paisas, Oficina de Envigado

The criminalization of these groups coincided with a larger battle over extradition fought by the Medellin Cartel and its leader Pablo Escobar against the government. This fight eventually spread to other parts of his organization. When Escobar killed two of their close associates, Fidel Castaño and his brothers, Carlos and Vicente, teamed with Diego Murillo, alias “Don Berna,” to form a group called People Persecuted by Pablo Escobar (Perseguidos por Pablo Escobar – PEPES). They used Carlos as their intermediary with the police, who worked closely with the paramilitary group to gun Escobar down in December 1993. Fidel mysteriously disappeared shortly thereafter. One story is that he died fighting the Popular Liberation Army (Ejercito Popular de Liberacion – EPL). Another is that Carlos killed him in a family dispute. In either case, the core of the paramilitary group that he and Don Berna had created remained.

The second generation of paramilitaries came from the PEPES. The remnants of this group formed the Peasant Self-Defense Forces of Cordoba and Uraba (Autodefensas de Cordoba y Uraba – ACCU). In 1996, the ACCU created a loose federation of self-defense groups comprised of seven regional organizations known as the United Self-Defense Forces of Colombia (AUC). These paramilitary groups were able to establish local fiefdoms in the main areas of guerrilla influence and drive out the rural population that they accused of collaborating with the rebels.

The AUC’s emergence coincided with a shift in the drug trafficking industry. Following the destruction of the Medellin Cartel and the subsequent dissolution of the Cali Cartel, the market became segmented, giving rise to about 500 small micro-trafficking groups. Leftist guerrillas from the Revolutionary Armed Forces of Colombia (FARC) also began exerting more territorial control over areas where drug crops were harvested and drugs were produced. The result was near-inevitable conflict between the two remaining super-structures as the paramilitaries fought the guerrillas for control of the means of production of the drug crops, entering by force — often with the support and assistance of the Colombian army — and carrying out selective assassinations and massacres that generated massive displacement and widespread terror.

The profits from their war spoils allowed the AUC to grow exponentially and create an army of more than 30,000 soldiers. But the source of this profit, principally drugs, placed the group in the crosshairs of the United States government, which sought to break up what had become arguably the largest drug trafficking organization in the world. Sensing a showdown and already facing a series of indictments in the US for drug trafficking, the paramilitaries sought a way out by negotiating a peace deal with the Colombian government.

In 2020, InSight Crime published a new investigation, revealing how Guillermo León Acevedo Giraldo, alias “Memo Fantasma,” a former member of the AUC had been living in luxury in Madrid, Spain. He was arrested in June 2021.


The Castaño brothers are considered the founders of Colombia’s paramilitary movement, but each of the regional groups that comprised the AUC also had its own leadership.


At the height of its power, the AUC operated in two-thirds of Colombia, with a particularly strong presence in the Caribbean Coast region, especially in Uraba, a region located in northwestern Colombia near the Panamanian border.

Allies and Enemies

The AUC fought against the FARC for control of areas that were strategic in the drug trade, and targeted communities it believed to be loyal to the FARC, perpetrating massacres and other atrocities. At the same time, the AUC counted on the support of military and political officials.


Between 2003 and 2006, the AUC and the Colombian government hammered out a peace agreement, and numerous paramilitary fronts demobilized. The shortcomings of the process, however, were immediately apparent. The government lacked the infrastructure to verify who the demobilized paramilitaries were and whether they had turned in all their weapons. Some paramilitary groups deliberately duped the government, handing in old and poorly maintained weapons and conscripting civilians to pose as paramilitary soldiers.

These groups began operating under new names even before the demobilizations officially ended in 2006. The new groups — now referred to as “criminal bands” or BACRIMs, for the Spanish acronym — include the Urabeños, the Rastrojos, ERPAC, the Paisas, the Machos, Aguilas Negras, and Renacer, among others. These groups are now dedicated to drug trafficking and organized crime, as well as attacks on civilians, especially activists and community leaders.

For many Colombians, the peace process and the AUC’s demobilization did not improve their situation. While more than 30,000 paramilitaries demobilized, many remained at large or abandoned the process and have since been implicated in grave human rights violations, drug trafficking, extortion, kidnappings and many other criminal acts.

The paramilitaries’ legacy extends beyond security. AUC members infiltrated the state and political parties, which has led to a series of investigations — in which prominent legislators have been charged — that have revealed what is known as the “parapolitics” scandal. The tradition of corruption continues to undermine and demoralize the Colombian government, and remains an integral factor in the ongoing violence in the country.

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