The Afghan native pleaded guilty to conspiracy to use weapons of mass destruction, conspiracy to commit murder in a foreign country and providing material support for a terrorist organization. He faces a life prison sentence without parole at a sentencing in June.
He said the terrorism plot was aimed at the city subway system but wouldn't name a specific target when asked by U.S. District Judge Raymond Dearie.
"This was one of the most serious terrorist threats to our nation since September 11th, 2001, and were it not for the combined efforts of the law enforcement and intelligence communities, it could have been devastating," said Attorney General Eric Holder.
Zazi was arrested in the fall after arousing authorities' suspicions by driving cross-country from Denver to New York around the anniversary of the Sept. 11, 2001, attacks.
"There is no question the NYPD and the FBI together stopped a plot that would have really hurt this city," Mayor Bloomberg said. "When you see the charges, this was not an amateur operation. It was a very serious plot against New York City, and fortunately, the great work by the FBI and the NYPD together stopped this plot. Let us just hope they stop the next one."
Zazi said he agreed to the bomb plot because of the United States' military action in Afghanistan. He says he received training in Pakistan.
Zazi said he went to Pakistan in 2008 to join the Taliban and fight against the U.S. military, but was recruited by the terrorist network and went into a training camp.
Zazi said he received training from al-Qaeda on constructing the explosives for the planned attacks in the United States. According to investigators, Zazi had discussions with al-Qaeda leaders about target locations, including subway trains in New York City.
Zazi returned to the United States in January 2009 and moved to Denver. Beginning in June 2009, he began reviewing the bomb-making notes from his training and conducting research on where to buy the ingredients for the explosives. Zazi then traveled to New York and met with others to discuss the plan, including the timing of the attack and where to make the explosives.
Zazi returned to Denver and used the bomb-making notes to construct the explosives for the detonator components of the bombs. In July and August 2009, Zazi purchased large quantities of components necessary to produce TATP and twice checked into a hotel room near Denver, where bomb making residue was later found.
On Sept. 8, 2009, Zazi rented a car and drove from Denver to New York, taking with him the explosives and other materials necessary to build the bombs. Zazi arrived in New York City on Thursday, Sept.10, 2009. Zazi and others intended to obtain and assemble the remaining components of the bombs over the weekend and conduct the attack on Manhattan subway lines on Sept. 14, Sept. 15, or Sept. 16, 2009.
Zazi's plan fell apart shortly after arriving back in New York. Zazi realized that law enforcement was investigating his activities, so he and others discarded the explosives and other bomb-making materials. Zazi then traveled back to Denver. He was arrested on Sept. 19, 2009.
"This attempted attack on our homeland was real, it was in motion, and it would have been deadly. We were able to thwart this plot because of careful analysis by our intelligence agents and prompt actions by law enforcement. They deserve our thanks and praise," Holder said.
"Today's plea is an important development in this complex and ongoing criminal investigation and intelligence operation that in many ways illustrates the evolving nature of the terrorist threat today," said FBI Deputy Director John S. Pistole.
This case is being prosecuted by the U.S. Attorney's Office for the Eastern District of New York, with assistance from the U.S. Attorney's Office for the District of Colorado and the Counterterrorism Section of the Justice Department's National Security Division. The investigation is being conducted by the New York and Denver FBI Joint Terrorism Task Forces, which combined have investigators from more than fifty federal, state and local law enforcement agencies.