Pakistani-American David Coleman Headley, accused of plotting the Mumbai attacks at the behest of the LeT and conspiring to target a Danish newspaper, on Thursday pleaded guilty to all terror charges before a U.S. court in Chicago.

Headley, 49, who faces six counts of conspiracy involving bombing public places in India, murdering and maiming persons in India and providing material support to foreign terrorist plots and LeT; and six counts of aiding and abetting the murder of U.S. citizens in India, could have been sentenced to death if convicted.

But his plea agreement with federal prosecutors ruled out the death penalty and extradition to India, Pakistan and Denmark, provided that he cooperates with the government’s terrorism investigations.

“Headley will cooperate in foreign investigation conducted in the US,” his lawyer John Theis told reporters after the hearing.

Headley, a Chicago resident who was arrested by the FBI’s joint terrorism task force on October 3, 2009, told U.S. District Judge Harry Leinenweber that he wanted to change his plea to guilty, in an apparent bid to get a lighter sentence than the maximum death penalty.

Son of a former Pakistani diplomat and a Philadelphia socialite, Headley, who was wearing an orange jumpsuit with hands and legs shackled, admitted guilty in all 12 counts during half an hour long hearing.

He also admitted using his friend Tahawwur Rana’s immigration company as a cover for surveillance activities in India and Denmark on behalf of Pakistan-based terrorist groups, including LeT.

Headley, admitted that he participated in planning the November 2008 terrorist attacks in Mumbai, India, as well as later planning to attack a Danish newspaper.

He also admitted that he attended training camps in Pakistan operated by Lashkar-e-Taiba on five separate occasions between 2002 and 2005.

In late 2005, Headley received instructions from three members of Lashkar to travel to India to conduct surveillance, which he did five times leading up to the Mumbai attacks three years later that killed six Americans among 166 people and wounded hundreds more.

A 35-page plea agreement containing a detailed recitation of Headley’s participation in terror conspiracies was presented when he changed his plea to guilty.

“By this plea agreement defendant agrees to enter a voluntary plea of guilty to all counts,” said the plea agreement of Headley.

Earlier, Headley was produced before the court under unprecedented security arrangements. Security forces along with sniffer dogs were deployed around the court. Special metal detector doors were erected at the entrance of the packed court room.

Headley has cooperated with the government since he was arrested on October 3, 2009, and the agreement states that he “has provided substantial assistance to the criminal investigation, and also has provided information of significant intelligence value.”

In light of Headley’s past cooperation and expected future cooperation, the Attorney General of the United States has authorised the United States Attorney in Chicago not to seek the death penalty against Headley, the plea said.

Regarding sentencing, which will be deferred until after the conclusion of Headley’s cooperation, the plea agreement calculates an anticipated advisory sentencing guideline of life imprisonment.

“Today’s guilty plea is a crucial step forward in our efforts to achieve justice for the more than 160 people who lost their lives in the Mumbai terrorist attacks. Working with our domestic and international partners, we will not rest until all those responsible for the Mumbai attacks and the terror plot in Denmark are held accountable,” said Attorney General Eric Holder.

“Not only has the criminal justice system achieved a guilty plea in this case, but David Headley is now providing us valuable intelligence about terrorist activities. As this case demonstrates, we must continue to use every tool available to defeat terrorism both at home and abroad,” it said.

Earlier, Union Home Secretary G.K. Pillai had said that if Headley gets severe punishment and comes out of the judicial process, it would be easier for India to get access to him in jail.

“If he is given a light sentence, it would not only be disappointing but we will be registering a very strong protest with the U.S.,” Mr. Pillai told a news channle in New Delhi.

The American terror suspect had got away with a lesser sentence after he was arrested in 1998 for smuggling heroin into the U.S. from Pakistan as he cooperated with the investigation in the case.

He was sentenced to less than two years in prison and thereafter went to Pakistan to conduct undercover surveillance operations for the Drug Enforcement Administration.