David Coleman Headley, 52, had pleaded guilty to carrying out spying missions on downtown Mumbai for the Pakistani terrorist organisation Lashkar-e-Taiba (LeT) that was behind the attacks.
He was sentenced on 12 counts in a Chicago jail but had struck a plea deal with prosecutors to avoid the death penalty or extradition to India.
Headley, a Pakistani American from Chicago, visited India five times between 2006 and 2008, and created maps and took video footage and GPS coordinates of several of the attack sites, including the Taj Mahal hotel, Oberoi hotel and Nariman House Jewish centre.
His surveillance work provided vital information for the 10 LeT terrorists and their handlers, who launched the attack on November 26, 2008, holding the city under siege for three days and leaving 166 people dead, including British millionaire Andreas Liveras.
The Frontline investigation of him is well worth watching LINK