The Conquering Self-Defense Forces of the Sierra Nevada (Autodefensas Conquistadoras de la Sierra Nevada – ACSN), also known as “Los Pachenca,” are an armed group that emerged following the demobilization of paramilitary organizations in Colombia in the early 2000s.

Since then, the ACSN have consolidated their power in the Sierra Nevada de Santa Marta, in Magdalena department, where they control multiple drug trafficking corridors and run extensive extortion networks. From there, they have expanded into other regions, establishing themselves as one of the main criminal actors shaping illicit economies in northern Colombia.

What Is the History of the ACSN?

The ACSN emerged from the demobilization of the Tayrona Resistance Bloc (Bloque Resistencia Tayrona – BRT) of the United Self-Defense Forces of Colombia (Autodefensas Unidas de Colombia – AUC), under the command of Hernán Giraldo Serna, alias “El Patrón.”

The BRT began as a protection group for politicians, businesspeople, and marijuana growers—known locally as “marimberos”—in the Sierra Nevada de Santa Marta region. After the expansion of the Revolutionary Armed Forces of Colombia (Fuerzas Armadas Revolucionarias de Colombia – FARC), Giraldo expanded his group and renamed it the “Autodefensas del Mamey.” By the late 1990s, the group was calling itself the Peasant Self-Defense Forces of Magdalena and La Guajira (Autodefensas Campesinas del Magdalena y La Guajira – ACMG).

After joining the AUC structure coordinated by brothers Carlos and Vicente Castaño, Giraldo’s group gained power and influence in Magdalena and the neighboring department of La Guajira. Following internal disputes, the group was renamed the Tayrona Resistance Front (Frente Resistencia Tayrona) in 2002 and later reorganized as the Tayrona Resistance Bloc (Bloque Resistencia Tayrona – BRT) in 2005.

The BRT demobilized in February 2006, and in 2008, Giraldo was extradited to the United States. However, he left behind an extensive network of sons, brothers, and nephews who continued to lead the criminal operations of the Caribbean Office (Oficina del Caribe), a criminal network created by Giraldo in 2003 and also known as the Giraldo network.

In 2012, the group entered into a dispute with the Gaitanist Self-Defense Forces of Colombia (Autodefensas Gaitanistas de Colombia – AGC), also known as the Urabeños and the Clan del Golfo, over control of territories that were key to drug trafficking. The clashes left more than 150 people dead within a few months, according to media reports from the time.

The conflict began to ease after Jesús María Aguirre Gallego, alias “Chucho Mercancía” or “Chucho Pachenca,” a former AGC lieutenant, took control of the Giraldo clan in 2013.

Under “Chucho Mercancía,” the Gaitanistas and Giraldo’s successors became allies and worked together to move drugs out of northern Colombia. It was also during this period that the group adopted the name Los Pachenca.

Despite a period of relative calm that lasted several years, Los Pachenca’s position weakened in the late 2010s due to internal divisions and operations by the security forces. The first major blow came with the arrest of the group’s second-in-command, John Salazar Salcedo, alias “Flash,” in May 2019. Just one month later, Chucho Mercancía was killed by authorities, allegedly after being betrayed by someone in his inner circle.

After Mercancía’s death, Giraldo’s nephew, Deimer Patiño Giraldo, alias “80,” took over leadership of the group, which adopted a new name: the Conquering Self-Defense Forces of the Sierra Nevada (Autodefensas Conquistadoras de la Sierra Nevada – ACSN). Chucho Mercancía’s death also reignited tensions with the AGC, and the two groups once again began fighting over key drug trafficking areas in the Caribbean.

However, just one year later, 80 was killed during a police operation. Police identified several possible successors, most notably the Castillo brothers: Fredy Castillo Carrillo, alias “Pinocho,” and Carmen Evelio Castillo Carrillo, alias “Muñeca.”

In January 2021, Hernán Giraldo returned to Colombia after serving a 12-year prison sentence on drug trafficking charges in the United States. However, he was soon back behind bars after being accused of sexually abusing minors during the years he was imprisoned in Colombia.

In late 2022, the ACSN asked to be included in “Total Peace,” Colombian President Gustavo Petro’s flagship policy, which called for talks with any armed group willing to negotiate with the government. When the state offered a six-month bilateral ceasefire in January 2023 to groups participating in the talks, the ACSN accepted.

However, the negotiations did not progress beyond preliminary informal talks, and when the ceasefire expired in June 2023, the government did not respond to the ACSN’s calls to renew it at that time.

In early August 2024, Gustavo Petro’s government announced, through an official resolution, the start of “socio-legal talks” with the armed group. This classification meant that the government did not recognize the group as having political status. In response, the group announced a halt to its “military operations.”

Although government delegates and representatives of the armed group were appointed, the formal launch of the talks kept being postponed. Meanwhile, operations against the group continued.

In April 2025, the army attacked an ACSN camp in Magdalena, killing three combatants. As a result, the group suspended the outreach process with the government.

Four months later, in August 2025, the Colombian government designated the ACSN as an Organized Armed Group (Grupo Armado Organizado – GAO), meaning they are targeted under the rules of International Humanitarian Law (IHL).

Although the government continued military operations against the group following the designation, it also kept communication channels open with the group in hopes of resuming the dialogue process.

In February 2026, the government and the ACSN announced the signing of a de-escalation agreement under which the group committed to halting offensive actions against the security forces and protecting communities. However, this did not stop clashes between the army and the group. Following a military operation against it in June 2026, the group clashed with the army and blocked the main highway connecting several departments in northern Colombia for more than 36 hours.

Since President Abelardo de la Espriella took office in August 2026, the ACSN have been one of the armed groups most heavily affected by state operations, suffering significant losses within their ranks.

Who Are the Leaders of the ACSN?

Since the group’s formation, the leadership of the ACSN has been linked to Hernán Giraldo and his extensive family network. However, Giraldo has denied having ties to the group, and it is unclear how much influence he has over its day-to-day operations.

The ACSN are currently led by brothers Fredy Castillo Carrillo, alias “Pinocho,” and Carmen Evelio Castillo Carrillo, alias “Muñeca,” both of whom were previously members of the BRT.

Pinocho was extradited to the United States in 2008 to face drug trafficking charges. After serving his sentence, he was deported to Colombia in 2011. In 2022, he was arrested in Spain and extradited to Colombia to face new charges of murder and criminal conspiracy. In June 2023, he was released following a controversial court ruling. Although the decision was later overturned, Pinocho remains free.

Muñeca, meanwhile, was captured in June 2024 in the city of Pereira, in Risaralda department.

In September 2026, José Pérez Villanueva, alias “Cholo,” one of the group’s main leaders below alias “Pinocho,” was killed in an operation by Colombian authorities in the city of Santa Marta. This triggered an armed strike in parts of Magdalena and La Guajira departments. Orlando Pérez, alias “Patilizo,” and John Rafael Salazar, alias “Comando 200,” are two other group leaders prioritized in the De la Espriella government’s offensives.

Where Do the ACSN Operate?

According to security force figures, by the end of 2025 the ACSN had around 620 members, including 352 armed members and 268 people in support networks.

The group’s main stronghold is in the Sierra Nevada de Santa Marta, but its influence extends toward the Venezuelan border in La Guajira department and into northern Cesar. More recently, the group has expanded into other municipalities in La Guajira and Cesar, as well as into other departments such as Santander and Norte de Santander, the latter of which is strategically important because it borders Venezuela.

Its control over the region has also allowed it to establish extensive extortion networks. The group collects regular payments from businesses and residents in these areas, particularly in the tourism sector, which has grown along the beaches surrounding the Sierra Nevada. It also profits from illegal land sales in the region, pressuring property owners to sell and hand over a percentage of the proceeds to the group. If an owner refuses, the group seizes the property, forcibly displaces the owner, and then sells the land directly.

Who Are the ACSN’s Allies and Enemies?

The Gaitanistas have been both one of the ACSN’s main allies and one of their fiercest enemies. Although the two groups initially clashed, the ACSN spent several years serving as one of the Gaitanistas’ main drug trafficking operators in northern Colombia.

Since 2021, however, the two groups have been fighting a brutal war for control of drug trafficking in the departments of Magdalena, La Guajira, and Cesar. The conflict has even spread to the Norte de Santander department.

The ACSN have also established ties with small groups of hitmen, particularly in urban areas where they have a presence.

What Lies Ahead for the ACSN?

Since their formation, the ACSN have repeatedly demonstrated their resilience and ability to recover from setbacks. This is largely due to their longstanding presence in the Sierra Nevada de Santa Marta and the power the Giraldo clan holds in these territories. More than three decades of uninterrupted influence by the Giraldo family and its associates have created social, family, and community networks that have left the group deeply entrenched and able to withstand attacks from both the security forces and criminal rivals such as the Gaitanistas.

Despite the De la Espriella government’s sustained operations against the group, the armed structure is unlikely to disappear. The ACSN operate as a network that adapts to the loss of its leaders and has managed to anchor its illegal activities in extensive criminal governance, social control, and territorial presence across large areas of northern Colombia.