(CNN) -- A Massachusetts man will be sentenced Thursday after his conviction on multiple terrorism conspiracy charges in a case that raised questions about how terror suspects can be prosecuted.
Tarek Mehanna, 29, was found guilty in December of conspiring to help al Qaeda, conspiring to commit murder in a foreign country and making false statements.
He could face up to life in prison.
Prosecutors say Mehanna traveled to Yemen to receive training aimed at killing American soldiers and supporting terrorism at home.
After returning to the United States, they say, he provided material support by translating and posting on the Internet al Qaeda recruitment videos and other documents.
His lawyers say that in collecting and distributing jihadist propaganda he was doing nothing more than exercising his First Amendment right to free expression. They point out that some of the material he translated involved mujahedeen fighting the Soviet occupation of Afghanistan more than 20 years ago.
Legal experts have questioned the implications of the case, debating the extent of free speech protection and how and when authorities can move against someone who is believed to be engaged "preterror"-related activity.
"Mr. Mehanna's efforts to use and support violence followed no predefined path and knew no bounds," said Richard DesLauriers, the special agent in charge of the Boston FBI in December. "The FBI fulfilled its most important mission by stopping Mehanna's conspiracy to support terrorism, the goal of which was an unlawful affront to our nation's cherished ideal of peaceful dissent."
His supporters, meanwhile, have pledged their backing online, setting up a website in his defense.
Mehanna earned a doctorate at the Massachusetts College of Pharmacy and Health Sciences, where his father was also a professor.