New York (CNN) -- Closing arguments concluded Tuesday afternoon in the trial of Ahmed Khalfan Ghailani, accused by the United States of conspiring to bomb U.S. embassies in Kenya and Tanzania in 1998.
The bombings, for which al Qaeda claimed responsibility, killed 224 people, including a dozen Americans, and wounded thousands of others.
Ghailani's defense attorney, Peter Quijano, told the jury in U.S. District Court Tuesday that Ghailani was used by al Qaeda. "Call him a dupe, call him a pawn -- used, set up like a bowling pin, in the immortal words of Jerry Garcia," Quijano said, "but don't call him guilty."
The prosecution, which made its closing arguments on Monday, accused the 36-year-old Tanzanian national of mass murder. Assistant U.S. Attorney Harry Chernoff said Ghailani played a key role in securing the trucks that carried the bomb in Tanzania and securing other materials.
"He is a mass murderer who has the blood of hundreds on his hands," Chernoff told the jury.
The trial, which began in October, has moved more quickly than originally anticipated. Jurors listened to weeks of testimony from witnesses who were flown in from Kenya and Tanzania to testify, and jurors looked at dozens of government exhibits.
The defense called no witnesses and the defendant did not take the stand. At the onset of the trial the presiding federal judge barred prosecutors from calling a crucial witness, with the judge saying the government had obtained the identity and location of the witness through Ghailani when he was held and interrogated at a jail overseas run by the CIA.
Ghailani is the first detainee who's been held at Guantanamo Bay in Cuba to be tried in civilian court. He was captured in Pakistan in 2004, moved to Guantanamo in 2006 and transferred to a federal prison in New York last year.
Throughout the trial, the defense painted Ghailani as a local who knew how to get things done in Tanzania and whose knowledge al Qaeda exploited unbeknown to him.
The defense also questioned the witnesses' recall of events that happened so long ago, and portions of the FBI's original investigations in Kenya and Tanzania.
Prosecutor Chernoff said what the defense chiefly did on cross-examination was attack witness after witness. "Did it pay off? No," he told the jury.
The government rejected the claim that Ghailani was duped into participating, pointing to evidence of his activities in Tanzania in obtaining gas tanks and his presence in Dar es Salaam, Tanzania, and Mombasa, Kenya, with other members of the bomb plot at various times.
"This is Ghailani, " Chernoff said Monday, pointing at the defendant, who at times appeared to be joking and laughing with his attorneys when the jury was not present. "This is al Qaeda, this is a terrorist. This is a killer. I ask that you return a verdict of guilty on all counts."
The jury is expected begin deliberations Wednesday.