Updated

A Massachusetts man is facing life in prison after he was convicted Wednesday of plotting to behead blogger Pamela Geller and other Americans on behalf of the Islamic State terrorist group over a Prophet Muhammad cartoon contest she organized in 2015.

Jurors found David Wright, 28, guilty of all charges, including conspiracy to provide material support to a designated foreign terrorist organization and conspiracy to commit acts of terrorism transcending national boundaries.

"I said a lot of fantastical things about what I intended, where I wanted to go and where I wanted to travel, and it was never real," Wright said last week when he took the stand in Boston's federal courthouse. "It was fantasy."

Wright conducted online research for guns, swords and tranquilizers that put people to sleep instantly. He created a Twitter page seeking recruits for their "martyrdom operation cell," collected a trove of horrific Islamic State group documents and videos and created a manifesto warning that America's "days are numbered," prosecutors said. Wright's uncle bought three large knives — one for each of them — for their attack on Geller, authorities say.

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Wright "was committed to ISIS, and knew exactly what he was doing," Assistant U.S. Attorney Stephanie Siegmann told jurors, using an acronym for the Islamic State group.

Prosecutors said Wright, his uncle and a third man conspired to kill Geller because they were upset she organized the 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 assigned to guard the event.

Wright's uncle, Ussamah Rahim, told Wright on 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," referring to police. Wright told his uncle that was "beautiful" and encouraged him to delete all the data from his computer before carrying out his attack.

Hours later, Rahim was shot and killed by authorities after he lunged at them with a knife when they approached him in Boston. The attack on Geller, who has spearheaded several events across the U.S. to decry Islamic extremism, was never carried out.

Wright cried on the stand when he spoke of his uncle, insisting that he didn't think Rahim was serious about the attack. Wright, who weighed more than 500 pounds in 2015, testified that he used ISIS propaganda to get attention but was just playing a role and never wanted to commit violence.

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"I didn't want my uncle to get hurt. I didn't want law enforcement to get hurt," Wright said. "I lost someone who was very close to me because I was so deluded and self-centered that I couldn't see beyond my own need for attention."

Prosecutors said Wright was the leader of the conspiracy and recruited his uncle and others to help him wage war on the U.S. Wright's uncle received directions about the plan to kill Geller from Junaid Hussain, an ISIS terrorist and hacker who was later killed in an airstrike in Syria, prosecutors said.

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

The Associated Press contributed to this report.