A military hearing on whether the Army psychiatrist charged in the Fort Hood shooting rampage can be forcibly shaved is set for next week.
Major Nidal Hasan is charged with shooting dead 13 people at the sprawling base in Texas in November 2009. He faces the death penalty or life in prison without parole if convicted.
He has grown a beard since the attack, which is against US Army regulations. However, his lawyers say his Muslim faith means he will die a sinner if he is clean-shaven.
The 41-year-old, who was born to Palestinian parents, has already been found guilty of contempt of court five times for refusing to remove his beard. He faces the prospect of soldiers being ordered to shave it for him.
The court proceedings were postponed in August over the dispute. The appeal on October 11 at Fort Belvoir in northern Virginia will hear from prosecutors and defense attorneys.
The former army psychiatrist's lawyers have said that forcibly shaving him – as previously ordered by trial judge Colonel Gregory Gross – would violate his right to religious freedom.
Military lawyers argued that the order was similar to "and no more invasive than" a judge's right to restrain a defendant who is disruptive during a court martial.