Sulaiman Abu Ghaith, Osama bin Laden’s son-in-law who was also a spokesperson for Al Qaeda and a close adviser to the terrorist mastermind, was convicted in federal court in New York City for providing material support to terrorists and conspiring to kill Americans.

Abu Ghaith, a 48-year-old from Kuwait, now faces life in prison for what prosecutors said on Wednesday was a prominent role in recruiting a new wave of potential terrorists. Prosecutors showed a photo of Abu Ghaith sitting alongside bin Laden and current Al Qaeda leader Ayman Al-Zawahiri on Sept. 12, 2001, the day after the attacks on the World Trade Center buildings and the Pentagon.

Abu Ghaith admitted bin Laden called him to his cave in Afghanistan after the 9/11 attacks and asked him to help spread the terrorist group’s message. He did so in a video the next day, and continued to evangelize for the terrorist network in the months that followed.

In one video made on Oct. 9, 2001, Abu Ghaith says “the storm of airplanes will not abate,” which prosecutors said was a reference to Al Qaeda’s plan to detonate shoe bombs on other aircraft.

Prosecutors said Abu Ghaith made several appearances at Al Qaeda training camps before the 9/11 attacks and helped bin Laden try to attract young followers for a new wave of suicide missions. A convicted terrorist corroborated part of that claim when he testified that he had seen Abu Ghaith at an Al Qaeda home for new recruits when they were both in Afghanistan in 2001.

The defense argued that Abu Ghaith’s video recordings were the opinions of an imam and not of a terrorist with advance knowledge of the 9/11 attacks. Any involvement with Al Qaeda he may have had, the defense said, was nonviolent. Abu Ghaith, taking the stand himself in an unusual move, said he had only been with bin Laden because it was too dangerous to travel down from the mountains.

But the jury took only about 24 hours to decide they didn't buy Abu Ghaith's argument. His sentencing is set for Sept. 8.

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