Four New York men were convicted of plotting to blow up synagogues and shoot down US military aircraft after a trial hinging on the testimony of a paid FBI informant, the federal prosecutor's office said.
James Cromitie, 44, and three others had been accused of wanting to wage Muslim jihad in their own country, attacking the Jewish house of worship and a Jewish community center in the Bronx, and firing Stinger missiles at planes at a nearby Air National Guard base.
They face sentences of up to life in prison.
"Homegrown terrorism is a serious threat," Manhattan US Attorney Preet Bharara said.
"The defendants in this case agreed to plant bombs and use missiles they thought were very real weapons of terrorism. We are safer today as a result of these convictions."
The jury in Manhattan federal court took a week to reach the verdict following a trial in which the court heard how an FBI informant lured the four men deeper and deeper into an extended sting operation.
Cromitie, David Williams, 29, Onta Williams, 34, and Laguerre Payen, 29, were arrested on May 20, 2009 in a dramatic scene when they had just planted what they believed to be explosives at their targets.
The bombs were duds and the gang, which was taped expressing anger at Jews in general and at the US-led war in Afghanistan, was under surveillance throughout.
The case was not without controversy, raising questions about whether the four men, with Muslim convert Cromitie at their center, had been entrapped.
Testimony revealed the extraordinary lengths the informant went to assist,persuade and even cajole the defendants into going through with their idea to blow up the synagogues and fire at the Stewart air base in Newburgh, New York state.
The informant offered Cromitie a lucrative payoff if he went ahead and opened the way for the gang to buy extremely hard-to-procure Stinger missiles, which in fact were just planted fakes.
The prosecution's success was an important victory for the government as it handles a constant trickle of so-called homegrown terrorism cases, many of them based on informant testimony and incomplete plots, rather than actual
attacks.
The US attorney's office said there was no doubt about the gang's intentions and motivations.
Cromitie said that "if he were to die a martyr, he would go to 'paradise.' He also expressed an interest in doing 'something to America,'" the prosecutor's office said in a statement after the verdict.
"The following month, Cromitie and the informant discussed Jaish-e-Mohammed, a Pakistan-based designated Foreign Terrorist Organization, with which the informant claimed to be involved, and Cromitie stated that he would be interested in joining the organization to 'do jihad.'