slim possibility of his extradition, Headley, 52, would have to violate his plea agreement by not cooperating with US government or any foreign government in future investigations and not being truthful, Acting US Attorney Gary S Shapiro told reporters.
In that case, his guilty plea, under which he cannot by extradited, would be null and void. Thereafter Headley could be subject to the extradition treaty between India and the United States, Shapiro said outside the US District Court here minutes after Headley was sentenced to 35 years in jail.
In a pre-sentencing memorandum, the US government had notified the Chicago court of the plea agreement it had with Headley, under which they would neither seek death penalty nor extradite him to India, Pakistan or Denmark.
India has said it will continue to pursue with its demand for Headley's extradition for his role in 26/11 attacks that killed 166 people, including six Americans.
"The plea agreement says that if he fails to cooperate or his cooperation is less than complete and truthful, the entire plea agreement can be voided," Shapiro said last night.
"Under the plea agreement, he cannot be extradited to India for the crimes he has been convicted here. But, if the plea agreement were voided then our agreement as to extradition is voided as well," he said.
Shapiro said that under the plea agreement, Headley is required not only to cooperate with the US, but also with foreign governments as well.
"He is required to cooperate with whomever we tell him to cooperate... If he fails to do that, or does it less than completely and honestly, we have the option to void his plea agreement.
"If we void his plea agreement then he is facing the original penalties that he would have faced without his cooperation. So it is a powerful incentive to keep cooperating and to do it truthfully," Shapiro said.
Headley had also made a last ditch effort to have his sentence reduced by writing an emotional letter to the judge that he was a changed man now and was sorry of what he did in the past.
However, US District Judge Harry D Leinenweber, while acknowledging the receipt of such a letter, publicly told Headley in the court room that he had difficulties in believing him given his past record.
"I do not have any faith in Mr Headley when he says that he is a changed person now. I do believe that it is my duty to protect the public from Mr Headley and ensure that he does not get into any further terrorist activities," the judge said.
Headley, a US citizen of Pakistani descent, was sentenced last night to 35 years in prison for a dozen federal terrorism crimes relating to his role in planning the November 2008 terrorist attacks in Mumbai, and a subsequent proposed strike on a newspaper in Denmark.
The LeT terrorist pleaded guilty in March 2010 to all 12 counts that were brought against him following his arrest in October 2009. Immediately after his arrest, Headley began cooperating with authorities.
Headley was ordered to serve 35 years, followed by five years of supervised release by US District Judge Harry Leinenweber. There is no federal parole and the defendant must serve at least 85% of the sentence.