Prosecutors also have praised Headley for testifying against Tahawwur Rana, the Chicago businessman convicted of providing aid to Lashkar and backing a failed plot to attack a Danish newspaper for publishing depictions of the Prophet Muhammad. Rana, sentenced last week to 14 years in prison, claimed his friend Headley duped him.

Prosecutors have recounted only in broad terms how Headley has shed light on the leadership, structure and possible targets of Lashkar-e-Taiba, which was believed to have ties to the Pakistani intelligence agency known as ISI. Headley has said his ISI contact was a ‘‘Major Iqbal,’’ who was named in the indictment that charged Headley.

The attackers arrived by boat on Nov. 26, 2008, carrying grenades and automatic weapons, and fanned out to hit multiple targets, crowded train station, a Jewish center and the hotel.

For his cooperation and guilty plea, Headley secured both a promise that he would not face the death penalty and would not be extradited to India. Late last year, India secretly hanged the lone gunman who survived the Mumbai attack, Mohammed Ajmal Kasab.

The 12 counts Headley pleaded guilty to included conspiracy to commit murder in India and aiding and abetting in the murder of six Americans, who included Americans Alan and Naomi Scherr.

After the attack, Kia Scherr helped start an organization called the One Life Alliance, which seeks to work against terrorism by promoting understanding and respect for the sacredness of life.

She wrote in an email Thursday from Mumbai that she has thrown herself into doing charity work in the city.

‘‘This is how I am surviving this event, which erased life as I knew it,’’ she said.

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