(CNN) -- Col. Gregory Gross, the judge who will oversee the military trial of Maj. Nidal Hasan, ordered the Army psychiatrist to be forcibly shaved for his trial, according to Tyler Broadway, a spokesman at Fort Hood.
The order is likely to trigger an appeal that would further delay the case, which has dragged on now since 2009.
Hasan's attorney had filed an appeal when Gross threatened to order the shaving but the appeals court said it wouldn't issue a decision until the shaving was actually ordered. Thursday's order by Gross opens the door for that appeal.
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 violates Army regulations and Hasan is still an officer in the U.S. Army and subject to regulations.
Hasan's court-martial had been scheduled to start last month at Fort Hood, in Killeen, Texas, where he is accused of killing 13 people and wounding 32.
His lawyers can now go 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.
The District of Columbia-based court is made up of five civilian judges appointed for 15-year terms by the president. Decisions of the court are subject to direct appeal to the U.S. Supreme Court. Such an appeals process could delay Hasan's criminal trial for months if not years.