One 2002 al-Qaida propaganda video — titled "Convoy of Martyrs" — features Osama bin Laden's son-in-law preaching over still-horrific scenes of a plane flying into one of the World Trade Center towers on Sept. 11. Another shows the son-in-law looking at bin Laden admiringly as the al-Qaida leader boasts that he knew the attack would make both towers fall.

How a jury interprets those videos could determine the outcome of a Manhattan trial where the son-in-low, Sulaiman Abu Ghaith, is charged with conspiring to kill Americans and providing material support to al-Qaida.

As a Kuwaiti imam recruited to be al-Qaida's chief spokesman in the months following Sept. 11, Abu Ghaith "allowed himself to be caught on tape committing his crimes ... because he never thought they'd be played in this courtroom," Assistant U.S. Attorney Michael Ferrara said Monday in a rebuttal at closing arguments.

"You are looking at a guilty man," the prosecutor told jurors, referring to Abu Ghaith. "You can convict the defendant on those videos alone."

The videos also demonstrated that Abu Ghiath was a more powerful speaker than bin Laden or other al-Qaida leaders who spoke on tape, said another prosecutor, John Cronan, in his closing.

"You heard them speak during this trial," he said. "They are dull. They were monotone. That man wasn't. He had energy. He had passion. He was dynamic. He could fire people up."

Abu Ghaith's attorney, Stanley Cohen, countered in his closing that there was no evidence his client had a senior position with al-Qaida. He accused prosecutors of seeking to inflame jurors by repeatedly showing them the martyr video and by endlessly referencing 9/11, even though Abu Ghaith isn't charged in the attack.

The video "was designed, it was intended to sweep you away in anguish, in pain, and to ask for retaliation," Cohen said.

The defense attorney later warned the jury that the videos were an "an invitation to speculate," and accused the government of "trying to steal your independence, to intimidate you and to frighten you into returning verdicts not based upon evidence, but fear."

Jury deliberations were set to begin on Tuesday.

Abu Ghaith, 48, who was brought to New York last year after his capture in Turkey, has pleaded not guilty charges he conspired to kill Americans and provided material support to al-Qaida by spreading its message of hate and inciting would-be militants to join its fight against the West. The defense has never disputed that Abu Ghaith associated with bin Laden after 9/11, but it contends that he went to Afghanistan as a religious scholar concerned about oppression of all Muslims and never swore an oath of allegiance to bin Laden.

Taking the witness stand last week, Abu Ghaith recounted how he was summoned to meet with bin Laden in a cave on the night of Sept. 11. When the attacks came up in the conversation, bin Laden told him, "We are the ones who did it," he testified.

"I want to deliver a message to the world. ... I want you to deliver that message," Abu Ghaith said bin Laden then told him.

Abu Ghaith claimed he worked off of talking points provided by bin Laden when speaking about al-Qaida, and that he had no intention of recruiting fighters for the group — testimony Cronan called misleading.

"This man was not Osama bin Laden's robot," he said. "He was not his puppet. ... He was no accidental terrorist."

The evidence includes another video from October 2001 in which Abu Ghaith is heard warning of further attacks in the wake of 9/11, saying, "The storm of airplanes will not stop." He also advises Muslims "not to board aircraft and we advise them not to live in high- rises and tall buildings."

Prosecutors have argued the wording is proof the defendant know in advance about the failed shoe-bomb airline attack by Richard Reid in December 2001. The defense sought to knock down the accusation by pointing to trial testimony by a convicted al Qaeda operative linked to Reid that indicated he never had any contact with or knowledge of Abu Ghaith.