Following on the heels of Carlos Castaño's murder disappearance, another former AUC leader has been assassinated:

Assassins in Colombia have killed a dissident leader of a right-wing paramilitary force who had harshly criticized his colleagues for trafficking in drugs as the organization embarked on American-backed disarmament negotiations with President Álvaro Uribe, Colombian officials said.

The leader, Carlos Mauricio García, 39, who went by the name Rodrigo Franco, was shot in the head as he walked along a trendy beachfront stretch on Friday night in the Colombian coastal city of Santa Marta.

Though no arrest has been made, Mr. García knew he had been a target since breaking with other commanders of the United Self-Defense Forces of Colombia while publicly accusing them of forming a drug cartel.

The drug issue is clearly the reason why. Consider this:

Mr. García had been particularly critical of the group's most powerful commander, Diego Fernando Murillo. He also warned of the risks the group posed for the government.

"As it continues to fight extradition, it is converting Colombia into a narco-democracy of small feudal states that are run by warlord narcos," he said in one e-mail message.

I cannot see how Uribe can make the case for his impunity amnesty plan now.