Did you need another reason to hate the Drug Enforcement Agency? Here's a good one, care of The New York Times:

American authorities sent David C. Headley, a small-time drug dealer and sometime informant, to work for them in Pakistan months after the Sept. 11, 2001, attacks, despite a warning that he sympathized with radical Islamic groups, according to court records and interviews. Not long after Mr. Headley arrived there, he began training with terrorists, eventually playing a key role in the 2008 attacks that left 164 people dead in Mumbai.

The October 2001 warning was dismissed, the authorities said, as the ire of a jilted girlfriend and for lack of proof. Less than a month later, those concerns did not come up when a federal court in New York granted Mr. Headley an early release from probation so that he could be sent to work for the United States Drug Enforcement Administration in Pakistan. It is unclear what Mr. Headley was supposed to do in Pakistan for the Americans.

"All I knew was the D.E.A. wanted him in Pakistan as fast as possible because they said they were close to making some big cases," said Luis Caso, Mr. Headley's former probation officer.

One senior American official knowledgeable about the case said he believed that Mr. Headley was a D.E.A. informant until at least 2003, meaning that he was talking to American agencies even as he was learning to deal with explosives and small arms in terrorist training camps. […]

Mr. Headley, 50, born in the United States to a Pakistani diplomat and Philadelphia socialite, has pleaded guilty in connection with the Mumbai plot and a thwarted attack against a Danish newspaper that published cartoons of the Prophet Muhammad.