(CNN) -- A military appeals court decided Thursday, October 18th that accused Fort Hood shooter Maj. Nidal Hasan can be forcibly shaved, despite his assertion that his religion requires he wear a beard.
Siding with the judge overseeing the trial, Col. Gregory Gross, the U.S. Army Court of Criminal Appeals ruled that the Religious Freedom Restoration Act does not allow Hasan to wear a beard during his upcoming court martial, as Hasan did not prove his beard was an expression of a sincerely held religious belief.
"We agree with the military judge's conclusion that petitioner's wearing of the beard denigrates the dignity, order, and decorum of the court-martial and is disruptive under the current posture of the case," the decision says.
Even if Hasan did wear the beard out of a sincere religious belief, the decision found that "compelling" government interests justified the judge's order for Hasan to be shaved.
The military psychiatrist is accused of opening fire in November 2009 at the Texas Army post's processing center, where soldiers were preparing to deploy to Afghanistan and Iraq.
The attack left 13 dead and 32 people wounded. Hasan was paralyzed from the waist down after police exchanged fire with him.
His court-martial had been scheduled to start in August. But the appeals court delayed its start to determine whether his beard can be forcibly shaved during trial.
Army regulations prevent soldiers from wearing facial hair while in uniform. Hasan, who is still a soldier, is a practicing Muslim and maintains he has the right to wear the beard under U.S. laws protecting religious freedoms.
At a hearing in August, Hasan spoke about the beard he had grown.
"Your honor, in the name of almighty Allah, I am a Muslim," he told Gross. "I believe that my religion requires me to wear a beard."
Prosecutors argued that Hasan should have to shave his beard, saying the facial hair would make it harder for witnesses to identify him in court.
Gross ordered that Hasan would have to shave, triggering the appeal from Hasan's lawyers that was decided Thursday.
The court's decision can be further appealed to the U.S. Court of Appeals for the Armed Forces, an independent tribunal with worldwide jurisdiction over active-duty members of the U.S. armed forces and others subject to the Uniform Code of Military Justice.
Members of Hasan's defense team have indicated they plan on appealing the decision, according to Fort Hood.
If convicted of the shooting, Hasan can be sentenced to death.
A U.S.-born citizen of Palestinian descent, the licensed psychiatrist joined the Army in 1997. Though he was scheduled to deploy to Afghanistan, he had been telling his family since 2001 that he wanted to get out of the military.
Hasan told his family he was taunted after the terrorist attacks of September 11, 2001. Investigations tied to the Fort Hood shootings found he had been communicating via e-mail with Anwar al-Awlaki, a radical Yemeni-American cleric killed last year in a U.S. drone attack.