A Bosnian-born US citizen has been convicted of plotting co-ordinated suicide bombings of New York subways in what federal authorities called one of the biggest terrorism threats to the country since the September 11, 2001 attacks.
A federal jury in Brooklyn on Tuesday found Adis Medunjanin, 28, guilty of all nine counts against him, including conspiring to carry out a suicide attack on US soil, receiving military training from al-Qaeda and plotting to kill US soldiers fighting in Afghanistan.
The jury deliberated for 10 hours over two days. Medunjanin faces possible life imprisonment when he is sentenced on September 7.
Najibullah Zazi, Medunjanin's accused co-conspirator, was arrested in September 2009, just days before Medunjanin and a third member of the plot, Zarein Ahmedzay, were preparing to carry out the attacks.
Ahmedzay and Zazi, both 27, who were high school friends of Medunjanin, pleaded guilty to planning the attacks with him. They are co-operating with the government and await sentencing.
Robert Gottlieb, Medunjanin's lawyer, indicated outside the court that he planned to appeal the verdict, citing "some serious legal issues" he wanted to address.
The planned attack on one of the world's busiest subway systems, with an average weekday ridership of 5.3m people, was at the behest of senior al-Qaeda operatives, according to testimony.
The trial provided a rare look into the group's inner workings and recruitment methods.
"His conviction stands as a stark reminder of terrorists' desire long after 9/11 to return to the city to kill more New Yorkers," said New York Police Commissioner Raymond Kelly.
As the verdict was read, Medunjanin, a resident of the New York City borough of Queens, looked over several times at his mother and sister, both of whom testified on his behalf, and raised his hand in a reassuring gesture.
Afterwards, his mother and sister, who was sobbing, left the courtroom and declined to speak to reporters.
Gottlieb said that while his client was convicted of all charges, the case spotlighted the importance of trying a case before a jury rather than in a military tribunal, like the case of Khalid Sheikh Mohammed, accused of being the mastermind of the September 11 attacks.
"The world and our national government should take note that this is the way crimes should be decided, whether or not someone is guilty - not in military tribunals, not in a star chamber, but in America," Gottlieb said.
Loretta Lynch, the US lawyer whose team prosecuted the case, said the trial showed the need for US authorities to monitor security threats as vigilantly domestically as overseas.
"The rise of homegrown extremism is an issue," Lynch told reporters outside the courtroom.
"This trial has afforded a rare glimpse into the inner workings of al-Qaeda, how they look for those who have connections to our homeland, how they recruit those who are disaffected and seeking a place to go," she added.
Prosecutors during the trial argued Medunjanin was "ready and willing to sacrifice himself to kill" at the command of al-Qaeda, saying he committed to carrying out a suicide attack on US soil, a mission given to him by al-Qaeda operatives he met in Pakistan.
"What he was willing to do was to strap a suicide bomb to himself, walk into a New York City subway and blow it up," Berit Berger, assistant lawyer, said in closing arguments last week.
Gottlieb conceded in his closing statement that Medunjanin traveled to Pakistan in 2008 in an attempt to join the Taliban and seek vengeance for perceived wrongs against Muslims.
But while Medunjanin was under the sway of al-Qaeda propaganda, he never intended to follow through with his friends' plan, Gottlieb told jurors.
"Adis' intent was to fight and protect Muslims," Gottlieb said. "That was the extent of his formulated intent and plan in his own mind."