FBI said that Headley was arrested by FBI's Joint Terrorism Commission Task Force on Oct 3 while boarding a flight to Philadelphia at O'Hare Internationla Airport.
The affidavit filed by the FBI in the Chicago Court, showed Headley exchanging numerous emails with the Chief of Pakistan Occupied Kashmir(POK) section of Harakat-Ul Jihad Islami(HUJI), a Pakistan based terrorist group.
In one of the emails, Headley had asked Illyas Kashmiri, Operational head of POK section of HUJI, which had a close link with Al Qaeda, whether the reason behind sending him to India was for surveillance of targets for new terrorist attacks.
Headley is also allege to have close link with LeT members who were identified in the affidavit as LeT A and LeT B. The affidavit also qouted Headley as planning to travel to Pakistan with LeT A and Kashmiri on Oct 10, 2009.
FBI said that all the emails revealed the terrorist outfit's strong intention of using the American citizen for terrorist activity in India.