BOSTON — Is a man charged with plotting to behead conservative blogger Pamela Geller a dangerous Islamic State group supporter who sought to wage war on the U.S.? Or is he a lost young man who never meant any harm?

That's what a panel of 12 jurors in Boston's federal courthouse has been tasked with figuring out in the case of 28-year-old David Wright.

Jurors began deliberating Tuesday after listening to three weeks of evidence and from Wright himself. They are set to resume deliberations Wednesday. Wright insists he pretended to be an Islamic State group follower to get attention online, but it was just a "fantasy."

Assistant U.S. Attorney Stephanie Siegmann, in her closing argument, dismissed Wright's defense as absurd, noting he never told law enforcement when he was questioned in 2015 that he believed it was just a game.

"Now, more than two years after he was arrested, the defendant has made up this ridiculous story to try to beat the charges, to deceive you," Siegmann told the jurors.

Wright, who appeared emotionless as the lawyers argued Tuesday, is charged with obstruction of justice, conspiring to provide material support to a designated foreign terrorist organization and conspiring to commit acts of terrorism transcending national boundaries. He could face up to life in prison if convicted.

Wright admitted to one of the obstruction of justice charges when he testified last week that he deleted all the documents from his computer after he found out his uncle was killed.

Prosecutors say Wright, his uncle and a third man agreed to kill Geller because she offended Muslims when she organized a Prophet Muhammad cartoon contest in Texas in 2015. During the contest, two other men opened fire outside and wounded a security guard before they were killed in a shootout with law enforcement.

Wright's uncle, Ussamah Rahim, told Wright in a recorded phone call later that month that he couldn't wait to attack Geller and decided instead to go after "those boys in blue," a reference to police officers, because they were the "easiest target." Wright told his uncle that was "beautiful" and that he felt "left out."

Hours later, Rahim was approached by officers in a Boston parking lot, pulled out a knife, moved toward the officers and was fatally shot, officials said.

Wright, who weighed more than 500 pounds (227 kilograms) and spent much of his time playing video games in 2015, testified he didn't believe his uncle was serious about killing police. When Wright learned his uncle was dead, reality came crashing in on him, defense attorney Jessica Hedges told jurors Tuesday.

Hedges accused prosecutors of trying to exploit the public's fear of the Islamic State group by repeatedly showing the disturbing videos and documents found on Wright's computer. Sharing terrorist propaganda, no matter how horrific, is not a crime, she said.

"Times like this, when fear runs high, the government sometimes sweep the fantasy fools, the fan boys, up with the real thing," Hedges told the jurors. "You mustn't let that happen here."

But Siegmann questioned why Wright transferred all the Islamic State group files from his computer onto a thumb drive when he wiped his computer clean if the documents weren't important to him. She also noted that Wright researched online about the material support law.

"If you think you're just playing a game, why would you be concerned about violating a law?" Siegmann asked.

The third man charged, Nicholas Rovinski, pleaded guilty last year to conspiracy and faces between 15 and 22 years in prison. Rovinski, of Warwick, Rhode Island, testified against Wright, telling jurors Wright said Geller "deserved to be beheaded" because she insulted Mohammad.

The attack on Geller, who has spearheaded scores of events across the nation to decry Islamic extremism, was never carried out.