During the summer of 2009, Zazi traveled to New York to meet with his conspirators, telling the jury, "We talked about if we were still into the plan. Zarein and Adis said 'yes.'"
The three men decided on suicide bombings at three different Manhattan subway locations during the Muslim holy month of Ramadan, according to Zazi. He testified that the men specifically targeted trains leaving Grand Central Terminal at rush hour in order to maximize the death toll. We hoped that "people would have a lot of fear," Zazi said.
Zazi then returned to Denver, where he rented a hotel suite and began mixing the chemicals necessary to carry out his terrorism plot, creating what he said was enough for three bombs. Once completed Zazi rented a car, loaded in the deadly chemicals, and drove to New York.
However, earlier e-mails he had sent to his al Qaeda handler had been intercepted by the F.B.I, and by the time Zazi reached the George Washington Bridge, which connects New Jersey and Manhattan, counterterrorism investigators were waiting for him.
Police followed his car and Zazi, realizing he was under surveillance, stopped at a Queens mosque and threw away the chemicals, goggles, and other bombmaking materials. Ahmedzay flushed some chemicals down the toilet, Zazi added.
He flew back to Denver, where he was contacted by the F.B.I and later arrested.
Zazi's guilty plea was part of a government cooperation agreement that guaranteed his testimony in Medunjanin's trial.
The Associated Press contributed to this article.