In their sentencing memorandum, prosecutors acknowledged that Headley played “an essential role in the planning of a horrific terrorist attack.”
“There is little question that life imprisonment would be an appropriate punishment for Headley’s incredibly serious crimes,” they said. But they added that his extensive cooperation had been of “significant value” to US anti-terror efforts.
Headley, 52, is unlikely to emerge from prison until he is well into his 80s.
Headley pleaded guilty in March 2010 to all 12 counts in his indictment. The charges included conspiracy to bomb public places in India, conspiracy to murder and maim persons in India, and six counts of aiding and abetting the murder of US citizens in India.
Among the dead were six American citizens.
Headley attended a series of training camps in Pakistan in 2002 and 2003. He later decided to change his name from Daood Gilani to David Headley to allow him to conceal his Pakistani ties and portray himself as an American in India.
Headley told investigators that he made five trips to Mumbai in 2006, 2007, and 2008 to survey and videotape potential targets for a planned assault team from the Pakistani terror group Lashkar-e-Taiba.
At one point he used a GPS device to pinpoint potential landing spots for the assault team along the shores of Mumbai harbor.
The attacks were carried out from Nov. 26 to Nov. 28, 2009 by 10 men trained by Lashkar-e-Taiba. They were armed with assault rifles, grenades, and improvised explosive devices, and they killed indiscriminately.