Via the internet he attempted to recruit other people to help him and made contact with an undercover FBI agent, according to CNN’s News Blog,
The attempted plot came to fruition as an FBI undercover agent posed as an al-Qaeda facilitator:
Nafis asked the undercover agent for 50-pound bags of what he thought were explosives. He then worked on putting together an explosive device.
“Nafis purchased components for the bomb’s detonator and conducted surveillance for his attack on multiple occasions in New York City’s financial district in lower Manhattan,” the press release from the Justice Department describing the criminal complaint said. “Throughout his interactions with the undercover agent, Nafis repeatedly asserted that the plan was his own and was the reason he had come to the United States.”
Nafis had considered other targets, such as “a high-ranking U.S. official and the New York Stock Exchange” but settled on the Federal Reserve because he felt it would be more detrimental to the US economy.
“In a written statement intended to claim responsibility for the terrorist bombing of the Federal Reserve Bank on behalf of al-Qaeda, Nafis wrote that he wanted to ‘destroy America’ and that he believed the most efficient way to accomplish this goal was to target America’s economy,” the Justice Department press release said. “In this statement, Nafis also included quotations from ‘our beloved Sheikh Osama bin Laden’ to justify the fact that Nafis expected that the attack would involve the killing of women and children.”Nafis will be charged with attempting to use a weapon of mass destruction and attempting to provide material support to al-Qaeda, according to the press release.
Source: Fed Terrorist a Bangladeshi National Who Came to the US to "Destroy America"