Guzman, 56, faces multiple federal drug trafficking indictments in the US and is on the Drug Enforcement Administration's most-wanted list.
The authorities identified the Camden ringleader as Jose Fonseca, 44, who was charged with multiple counts of drug trafficking.
He was convicted in Miami in 1992 of multiple charges including drug trafficking, and sentenced to 40 years.
Most particularly, his slogan – "peace without impunity" – sums up his claim that Farc leaders responsible for multiple murders, kidnappings, drug trafficking, arms smuggling and terrorism-related crimes will be allowed to walk away under Santos's peace plan.
Most sensitive of all is the matter of appropriate punishment for rebel commanders, many of whom have multiple convictions for murder, drug trafficking and other major crimes.
A federal appeals court has rejected an appeal by two brothers convicted in multiple murders to overturn their drug trafficking convictions, the United States attorney's office said.
"Castaño's sins are many and multiple and they're not just drug trafficking; they're also rape, pillage and plunder," said a high-ranking Bush administration official involved in shaping Colombia policy.
He faces multiple charges, including abuse of a corpse, tampering with evidence, drug trafficking and weapons violations.
The volumes, compared with drug trafficking, are tiny – a handful of Kalashnikovs, as opposed to cocaine smuggled in multiples of tonnes – and the gangs behind the trade are also often tight-knit groups.
Drug trafficking is widespread.
