Dylan Boyd, 24, was scheduled to be in federal court in Raleigh nearly a month after pleading not guilty along with four others to felony charges from an alleged conspiracy to attack the U.S. Marine Corps base in Quantico, Va., and targets overseas.
Boyd and the other men could face life in prison if convicted of the most serious charges at a trial scheduled to start Monday.
Court documents do not show how Boyd is supposed to plead Wednesday. A new court filing Wednesday by defense attorneys challenging the admissibility of the government's audio tapes at next week's trial does not list Boyd among the defendants.
Boyd's brother, Zakariya, pleaded guilty earlier this year to a single count of conspiracy to provide material support to terrorists.
Their father and the accused terrorism ring's leader, Daniel Patrick Boyd, 41, pleaded guilty in February to charges of conspiracy to provide material support to terrorists and conspiracy to murder, kidnap, maim and injure persons in a foreign country.
A federal indictment unsealed in 2009 alleges the seven accused men raised money to buy assault weapons and conduct training exercises, and that they arranged overseas travel and contacts to help others carry out violent acts on behalf of a radical jihadist political agenda.
The indictment paints Daniel Boyd, a drywall contractor, as an experienced jihadist who traveled to Afghanistan in 1989 to join the fight against Soviet occupation.
Prosecutors played audio tapes at a 2009 court hearing of Daniel Boyd talking about his disgust with the U.S. military, the honor of martyrdom and the need to protect Muslims.
The FBI said its 2009 search of Boyd's Johnston County home found about two dozen guns and more than 27,000 rounds of ammunition. Authorities have previously said the men trained in the weeks leading up to their arrest, practicing military tactics with armor-piercing bullets in rural North Carolina.