With the death of Pedro Guerrero Castillo, alias “Cuchillo,” and the arrest of his number two, Harold Humberto Rojas, alias “Loco Harold,” the Popular Revolutionary Antiterrorist Army of Colombia (ERPAC) does not have an obvious candidate to take the reins, in part because several mid-level commanders have also been captured or killed.

During the last twelve months two other senior members of the ERPAC and potential replacements for Guerrero, were also arrested. The first, Martin Farfan, alias “Pijarbey,” was captured in December 2009. Farfan, a former paramilitary of Bloque “Heroes de los Llanos” of the United Self-Defense Forces of Colombia (Autodefensas Unidas de Colombia – AUC), demobilized with Guerrero as part of the government’s peace process in 2006, but then left the process with Guerrero and became one of the founding members of the ERPAC. In May 2010, Jose Covey Romero Zarate, alias “Covey,” was arrested. He ran operations in the department of Vichada and was in charge of moving cocaine shipments into Venezuela.

The ERPAC was a military organization, with a hierarchy and clear chain of command. But with so many levels of the leadership decimated and in disarray, there may now be a vacuum in the eastern plains.

Given that, InSight gives you several groups and players with the potential to take advantage of the death of Guerrero:

1) Daniel Barrera, alias “El Loco.” Guerrero worked closely with Barrera (shown in photo above), one of Colombia’s top drug traffickers. He has long had presence in Meta, where the ERPAC have their headquarters. He will be keen to see the flow of cocaine from the eastern plains of Colombia continue. Barrera might either back an existing member of the ERPAC, although there are not any obvious candidates identified, or he may seek to place one of his own people there. Guerrero owed much of his rise to backing from Barrera, who is believed to have helped him kill his former boss, Miguel Arroyave, alias “Arcangel,” in September 2004, when the two were still part of the AUC. Barrera, however, has a problem. He is the number one target of the Colombian government. He is feeling so much pressure that sources tell InSight Crime he is seeking to hand himself into U.S. authorities in a third country like Curacao or Argentina where he may be residing.

2)Rastrojos. Another alternative is that Barrera asks his ally Luis Enrique Calle Serna, alias “Comba,” to take his Rastrojos into the five provinces that Guerrero controlled. The Rastrojos over the last four years have converted themselves into an organization with national reach and could easily send several hundred armed fighters into the ERPAC area.

3) Urabeños. The Rastrojos’ rivals, the Urabeños, would also be interested in moving into the eastern plains. The head of the Urabeños, Juan de Dios Usuga, alias “Giovanni,” worked with Miguel Arroyave as part of the AUC’s Bloque Centauros on the eastern plains, based in Meta. The Urabeños have tried in the past to move back into the area, but have always been expelled by the ERPAC. They may now try again.

4) FARC. Another option is that the Revolutionary Armed Forces of Colombia (FARC) could step up and take over some of Guerrero’s business. The FARC had an agreement with Guerrero, allowing him freedom of movement though some of their areas they control and selling him coca base, which he processed into cocaine hydrochloride (HCl). The FARC’s Eastern Bloc, although weakened by the death of its leader in September 2010, might try to move up its exportations of cocaine and reopen routes closed after the death of their principal drug trafficker, Tomas Medina Caracas, alias “Negro Acacio,” in September 2007.

5) Martin Llanos. Hector German Buitrago, alias “Martin Llanos,” was the leader of the AUC faction the Peasant Self Defense Forces of Casanare (ACC), with presence in the departments of Meta and Casanare. While the ACC were all but destroyed in an internal AUC war in 2004, Buitrago never turned himself in as part of the government’s peace process and is believed to still be active in the region. This may be the moment for him to recover ground he lost. He might also have the backing of Victor Carranza, a large landowner and emerald dealer who was once jailed, but never convicted, for forming paramilitary groups.

6) Victor Carranza. Known as the “Emerald Czar,” Carranza survived two assassination attempts (July 2009 and March 2010), allegedly at the hands of Guerrero, who was seeking to take over his interests in Meta and Vichada. Carranza, while he has been accused of paramilitarism, has never been convicted, but he is a huge landowner in Meta, and he is believed to be very influiential in the criminal underworld in the eastern plains. Indeed, there are many who believe that the pressure on Guerrero and ERPAC has come because of Carranza’s influence in Bogota’s circles of power.

Jeremy McDermott is co-founder and co-director of InSight Crime. McDermott has more than two decades of experience reporting from around Latin America. He is a former British Army officer, who saw active...