Updated

A prosecutor told jurors Thursday that a U.S. citizen went to Pakistan in 2008 with two others determined to kill American troops in Afghanistan, but a defense lawyer said the men were "immature, naïve and clueless" and easily manipulated by both al-Qaida and U.S. investigators.

Both versions of Adis Medunjanin's trip abroad were offered during closing arguments before a federal jury in Brooklyn begins deliberating the fate of the Bosnian-born Muslim who became a naturalized U.S. citizen.

Medunjanin is charged with nine crimes, including conspiring to use weapons of mass destruction and conspiring to provide material support to al-Qaida by prosecutors who say he returned to New York weeks after he left to begin planning a martyrdom operation to set off explosives in the city's subway.

Assistant U.S. Attorney Berit Berger said Medunjanin and the other two men quickly ditched their original plan to fight for the Taliban against Americans in Afghanistan when they connected with al-Qaida operatives in Pakistan who wanted them to return to America on a terrorism mission.

"This is Terrorism 101," she said. "The goal of this conspiracy was to kill as many people as possible."

Medunjanin has pleaded not guilty to charges he became an al-Qaida operative who discussed bombing movie theaters, Grand Central Terminal, Times Square and the New York Stock Exchange before settling on the city's subways.

The defense has argued that federal agents unfairly coerced Medunjanin into making incriminating statements after they intimidated his family.

The prosecution's case "brought to the surface the worst fears about our future ... A plot to bomb subways," but is not as clear-cut as the government claims, defense lawyer Robert Gottlieb told jurors.

Medunjanin traveled to Pakistan in 2008 with Najubullah Zazi and Zarein Ahmedzay. Zazi and Ahmedzay both pleaded guilty and cooperated against him.

Gottlieb called his client and the two other men "immature, naïve and clueless" when they set out for Afghanistan to fulfill some "romantic version of jihad. ... His plan and intent was to join the Taliban and stand up for what he believes in. That was his purpose."

Zazi, who testified as a government witness, learned about explosives at an al-Qaida training camp in Pakistan. Berger showed the jury pictures of a rocket propelled grenade and a bazooka, saying the defendant won a special lottery to shoot a bazooka.

She said al-Qaida leaders told them that "if you can't make a bomb, make something smaller" because in other missions, "people have failed because they tried to do something big and ended up not doing anything."

Medunjanin returned to New York, where he studied and worked as a doorman in a Manhattan building, in September 2008 while the other two came back the following January.

Zarein returned to his family in Queens while Zazi went to Colorado.

Zarein testified that the three agreed the New York subways would be a good target.

Berger said Zazi assembled a bomb out of household products in a Colorado hotel room before driving across America, arriving in New York on Sept. 10, 2009. She said the men realized they were being followed by law enforcement so Zazi dumped his bomb ingredients into a mosque toilet and flew back to Colorado.

Berger said Medunjanin loved Osama bin Laden more than himself — a claim the defense contested.

The prosecutor said the defendant was so frustrated that he could not carry out his suicide mission with the others that he finally got in his car on Jan. 7, 2010, and decided to crash it and kill other motorists. She said Medunjanin was speeding down the Whitestone Expressway at more than 90 mph when he wrecked.

"He was hoping to die and in the process to kill as many people as he could," she said, adding that the air bags in his car kept him from getting even a scratch and no other motorists were injured.

She played for the jury a 911 call the defendant made from his cellphone as he drove. He could be heard shouting: "We love ... We love death!"