Zazi and Ahmedzay, who testified as part of a plea deal, told jurors that the scheme unfolded after the trio traveled to Pakistan in 2008 to avenge the U.S. invasion of Afghanistan by joining the Taliban.
While receiving terror training at outposts in the South Waziristan region of Pakistan, al-Qaida operatives encouraged the American recruits to return home for a suicide-bombing mission intended to spread panic and cripple the economy. Among the targets considered were the New York Stock Exchange, Times Square and Grand Central Terminal, the men testified.
In a later meeting in New York, the plotters decided to strap on bombs and blow themselves up at rush hour on Manhattan subway lines because the transit system is "the heart of everything in New York City," Zazi said.
Zazi told jurors how he learned to extract explosives ingredients from nail polish remover, hydrogen peroxide and other products sold at beauty supply stores. When leaving Pakistan, he relocated to Colorado, where he perfected a homemade detonator in a hotel room and set out for New York City by car around the eighth anniversary of the Sept. 11 attacks.
The plot - financed in part by $50,000 in credit card charges - was abandoned after Zazi noticed that everywhere he drove in New York, a car followed.
"I think law enforcement is on us," he recalled telling Ahmedzay. Later, he said, he told Medunjanin in a text message, "We are done."