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, Virginia, 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 audiotapes 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.