The criminal case of alleged Ft. Hood shooter Maj. Nidal Hasan was delayed indefinitely by a U.S. Army appeals court on Friday to determine whether his beard can be forcibly shaved during trial.

The Army Court of Criminal Appeals issued a stay for an undetermined period in response to appeals filed by Hasan's lawyers.

Army regulations prevent soldiers from wearing facial hair while in uniform. Hasan, a practicing Muslim, maintains he has the right to wear the beard under U.S. laws protecting religious freedoms.

Hasan's court-martial had been scheduled to start last month at Fort Hood, where the military psychiatrist is accused of killing 13 people and wounding 32 in a 2009 shooting spree. But the proceedings have been delayed due to the legal questions over his beard.

Fort Hood said in a statement the appeals are to determine whether the federal Religious Freedom Restoration Act allows Hasan to keep his beard during trial.

Earlier this month, Col. Gregory Gross, the judge who will oversee the trial, ordered Hasan to be forcibly shaved for the proceedings.

The last time he was in court, Hasan told the judge, "Your honor, in the name of almighty Allah, I am a Muslim. I believe that my religion requires me to wear a beard."

Gross has said the beard violated Army regulations and Hasan was still an officer in the U.S. Army and subject to regulations.

According to the press release, the Army's appeals court will receive responses from the prosecution. After that, the court can order an oral argument or issue a ruling based on legal briefs submitted by both sides.

Depending on the outcome, the case can move forward and be returned to Col. Gross or Hasan's lawyers can go to the U.S. Court of Appeals for the Armed Forces. That is an independent court with worldwide jurisdiction over active-duty members of the military and others subject to the Uniform Code of Military Justice.

The District of Columbia-based court is made up of five civilian judges. Its decisions are subject to direct appeal to the U.S. Supreme Court.