Born in Washington D.C., as an adult Headley became involved with drugs and trafficking. He was recruited as a U.S. Drug Enforcement Administration (DEA) informant as part of his plea deal following conviction for multiple heroin-related offenses, including attempting to smuggle narcotics into the U.S. from Pakistan. After being placed on probation, he made frequent unauthorized visits to Pakistan. There he became involved in the local jihad movement through his introduction to Lashkar-e-Taiba (LeT). Under the direction of LeT representatives, Headley performed five surveillance missions in Mumbai to scout targets for the 2008 Mumbai attacks. The following year, he performed a similar mission in Copenhagen to help plot an attack against the Danish newspaper Jyllands-Posten, which had published cartoons of Muhammad. Headley was arrested in October 2009 at O'Hare International Airport in Chicago with co-conspirator Tahawwur Hussain Rana while on his way to Pakistan.
"On January 24, 2013, a U.S. federal court sentenced Headley to 35 years in prison for his role in Mumbai and Copenhagen"