David Coleman Headley, an American who has confessed to helping plan the 2008 terrorist attacks in Mumbai, told a Chicago court that he plotted a similar attack against a Danish newspaper with the support of a Pakistani terror group and the country’s intelligence agency, the ISI.

On his second day as the star prosecution witness in the terrorism trial of his childhood friend and alleged co-conspirator, Headley said his Pakistani handlers visited his Lahore home in November 2008. They directed him to lay the groundwork for an attack on Jyllands Posten, the Copenhagen newspaper that in 2005 published 12 cartoons of the Prophet Mohammed.

As part of an ongoing investigation, ProPublica reporter Sebastian Rotella and a team from FRONTLINE traveled to Copenhagen recently to investigate the reconnaissance mission that Headley undertook in early 2009. Tracing Headley’s path, the team ended at King’s Square, the heart of Copenhagen where Jyllands Posten was based at the time of Headley’s mission.

In testimony today, Headley described visiting the newspaper’s headquarters and deciding that the office building was a prime target. He was later directed by an Islamic militant with ties to Al Qaeda to plan for a “stronghold” attack on the newspaper, where hostages would be taken, killed and beheaded.

Headley has pleaded guilty to working with the terrorist organization Lashkar-i-Taiba, the militant Islamic group that carried out the attack on Mumbai that killed 166 people. Headley had spent two years casing Mumbai before the attack. In the current trial, Tahawwur Rana, a Chicago businessman who had known Headley since childhood, is accused of providing financial and logistical support for the Mumbai attacks.

Headley was arrested in October 2009, and has admitted his role in the Denmark plot. The attack on the newspaper was not carried out.

Tom Jennings is producing a documentary on David Coleman Headley scheduled to air on FRONTLINE on Nov. 22, 2011.

Tom Jennings