Mark Bowden: Killing Pablo: The Hunt for the World's Greatest Outlaw

"Are you sure we can do nothing?" he asked again. "Is there anything, anything we could do to earn a visa?"

"Even if you helped put the whole Cali cartel in jail we would not give you a visa," Toft told him.

And Juan Pablo left.

During the celebration at the embassy after Escobar was killed, Toft felt a knot in his stomach. He felt it all the while he was smiling, embracing colleagues, talking to the Colombian press. Toft was troubled by a feeling that somehow, they had sold their souls to the devil.

Even so, he framed a certificate presented by DEA Special Agent Kenny Magee to those directly involved in manhunt. It read, in part: "Because of your selfless dedication and willing sacrifices, the world's most sought after criminal was located and killed. . . ." At the bottom were the signature and thumbprint of Pablo Escobar.

In his briefings in Washington over the previous year, Toft had soft-pedaled evidence of links between his own agency and the vigilantes of Los Pepes. He knew his agents had seen self-confessed Los Pepes leaders at the headquarters of the Search Bloc, the police team funded and guided by the United States.

He knew that certain murders of Escobar associates by Los Pepes came after the victims had been located by U.S. intelligence, and the information had been passed to the Search Bloc. On the one hand, Los Pepes were dismantling Escobar's Medellin cartel and stripping away the layers of protection around him. On the other hand, their brutal methods troubled Toft's conscience.

Now, with Escobar dead, Toft worried that the effort against Escobar had created a monster. It had opened a bridge between the Colombian government, its top politicians and generals, and the rival Cali drug cartel - what the DEA came to call a "super cartel." In the years the Americans had focused on Escobar, Toft feared, the Cali cartel had consolidated its operations, cemented its relationship with the Colombian government, and emerged as a cocaine monopoly.

In 1994, Toft retired from the DEA.

"I don't know what the lesson of the story is," he said recently. "I hope it's not that the end justifies the means."