|Ghailani was arrested in Pakistan in 2004 and transferred to the US-run Guantanamo Bay prison in 2006 [AFP]
The first former Guantanamo detainee to be tried in a civilian court has been found not guilty on all but one of the 286 charges in the 1998 bombings of two US embassies in Africa.
A federal jury handed down the verdict on Wednesday to Ahmed Ghailani, a Tanzanian national who had been accused of conspiring in the car bomb attacks in Kenya and Tanzania that killed 224 people.
The jury found him guilty of one charge of conspiracy to damage or destroy US property by means of an explosive device.
Ghailani was cleared of 276 murder and attempted murder counts, along with five other conspiracy charges.
However, he faces a mandatory minimum sentence of 20 years after his conspiracy conviction.
"We respect the jury's verdict and are pleased that Ahmed Ghailani now faces a minimum of 20 years in prison, and a potential life sentence for his role in the embassy bombings," the US justice department said after the verdict.
'Efficient and fair'
Daphne Eviatar, from Human Rights First, said that the trial demonstrated the system works and that there was no need to keep the Guantanamo Bay facility open.
"What strikes me is how efficient, fair, and transparent the federal court prosecution was," she said.
"The questions today's verdict raise are why the government has not tried all terror suspects in federal court and when will the government announce additional prosecutions."
Ghailani was accused by government prosecutors of conspiring to carry out the attacks by purchasing a lorry and gas cylinders. But his lawyers argued that he was a dupe of the senior al-Qeada leaders and that he had no prior knowledge of their plans.
Under US law, prosecutors must prove that a defendant wilfully and knowingly took part in a plot.
Ghailani was arrested in Pakistan in 2004 and was transferred to the US-run Guantanamo Bay detention facility in Cuba in 2006.
The trial at a New York courthouse had been viewed as a possible test case for the US government's aim of putting other Guantanamo detainees on civilian trials on US soil.
Ghailani's prosecution also demonstrated some of the constitutional challenges the government would face if that happens.
On the eve of the trial last month, the judge barred the government from calling a key witness
because the witness had been identified as being subject to harsh interrogation techniques.
After briefly considering an appeal of that ruling, prosecutors forged ahead with a case that began 10 years ago in the prosecution of four other men charged in the same attacks in Tanzania and Kenya.
All were convicted and sentenced to life terms.
Ramzi Kassem, a lawyer for Guantanamo and Afghanistan's Bagram detainees, told Al Jazeera that the Ghailani verdict will add fuel to the debate in the US about whether to go with the regular court system versus military commissions.
"On the one hand, it can be characterised as a defeat for the [Barack] Obama administration because you've got a man that has been acquitted of over 280 charges," he said.
"But he was found guilty of one conspiracy count and that carries a minimum of 20 years to life. So it's not like the Obama administration isn't getting a conviction out of this case.
"I think that is something there for both sides to argue - that we should move forward with regular courts when you compare the military to the court system, and the other side will argue that this means military courts are the way to go."
However, David Remes, a lawyer for some of the detainees at Guantanamo, told Al Jazeera that little was likely to change as a consequence of the Ghailani ruling.
"The fact is though is that it won't have much impact in the long run - the [US] administration has already plotted its course, and this will only stand as background noise," he said.