Ghaith, 51, claimed the evidence did not support his conviction for conspiring to murder Americans, and that the indictment failed to detail how he had provided material support of terrorism.
However, the 2nd US Circuit Court of Appeals in Manhattan found “overwhelming” proof that Ghaith knew of al Qaeda’s goal of killing Americans and intended to participate, even if he did not know details of any specific planned act of terror, AP reported.
The court also said Gaith’s speeches telling Muslims it was their duty to fight for al Qaeda “provided material support to Al Qaeda by spreading its message to the world and encouraging others to join its terrorist cause.”
“Justice done,” the office of Acting US Attorney Joon Kim in Manhattan said on Twitter.
Ghaith served as a mouthpiece for Al-Qaeda after the September 11 terrorist attacks against the United States in 2001, as he recorded inflammatory videos to attract new members, prosecutors argued at his trial.
During his sentencing in 2014, bin Laden’s son-in-law was unrepentant, telling US District Judge Lewis Kaplan that “at the same moment where you are shackling my hands and intend to bury me alive, you are at the same time unleashing the hands of hundreds of Muslim youths.”
Ghaith, who sat with bin Laden in an Afghan cave hours after the attacks of September 11 attacks, was the most senior associate of bin Laden to be tried in a civilian court in the United States since the attacks.
A Manhattan federal jury convicted the Kuwaiti-born cleric on three counts: conspiring to kill Americans, conspiring to provide material support for terrorists and providing such support.
He is serving a life sentence at the “Supermax” prison in Florence, Colorado, which also houses Al-Qaeda operative Zacarias Moussaoui, 1993 World Trade Center bombing defendant Ramzi Yousef and 2013 Boston Marathon bomber Dzhokhar Tsarnaev, among others found guilty in terrorism cases.
Following the September 11 terrorist attacks, the US detained hundreds of individuals suspected of ties to Al-Qaeda, but instead of trying them in US courts, held the suspects for years without trial at the Guantanamo military prison in Cuba. Most inmates were subsequently cleared for release. The UN ruled that the practices at Guantánamo, including arbitrary detention without trial, blatantly violated international law.
As of now, only 10 of Guantanamo’s remaining 41 captives have been officially charged with crimes, according to the Miami Herald.