Federal prosecutors allege Ahmed Ghailani was part of an al-Qaida cell that bombed two U.S. embassies in Africa in 1998.
In closing arguments, the government called Ghailani a cold-blooded killer and terrorist. It said he bought a truck and explosive components for the bombers before slipping away to Pakistan.
The defense argued that Ghailani didn't know about the plot. His lawyer called him a "dupe" and a "fall guy" for senior terror operatives.
The attacks in Tanzania and Kenya killed 224 people, including a dozen Americans.
Deliberations began on Wednesday afternoon.
