WASHINGTON (CNN) -- A military appeals court halted the murder case against Maj. Nidal Hasan indefinitely on Friday to sort out issues surrounding a judge's threat to shave the beard the Army psychiatrist grew while awaiting trial in the 2009 Fort Hood killings.
The court martial was originally stopped on Wednesday and Hassan was fined $1,000 for remaining bearded, which violates Army regulations. The military judge in the case, U.S. Army Col. Gregory Gross, had previously held that Hassan's beard disrupts the court proceedings and held him in contempt of court five times, the Army said in a news release.
Hasan's court-martial had been scheduled to start Monday at Fort Hood, in Killeen, Texas, where he is accused of killing 13 people and wounding another 32. Gross, had threatened to have him forcibly shaved unless he got rid of the beard on his own.
It was unclear how long the case would be on hold.
Hasan had been expected to enter a plea during a Wednesday hearing, but the proceedings were halted by the appellate court. Hasan has previously expressed interest in pleading guilty, but military regulations bar a judge from accepting a guilty plea in a capital case.
Hasan is accused of opening fire at the post's processing center, where soldiers were preparing to deploy to Afghanistan and Iraq, in November 2009. The stay came the same day he was expected to enter a plea to the charges against him.
The issue surfaced in June, when a bearded Hasan -- who remains in the Army while awaiting trial -- appeared at a June hearing. Gross postponed that hearing, found Hasan in contempt of court at a July hearing, fined him $1,000 and warned him he would be shaved by force unless he got rid of it.
Hasan faces a possible death sentence if convicted. He was paralyzed from the waist down when police officers exchanged fire with him.
His lawyers had been seeking a delay of the case until December, but Gross refused and set Monday as the trial date.
Hasan, a U.S.-born citizen of Palestinian descent, who joined the Army in 1997. He had been scheduled to deploy to Afghanistan before the killings, but had been telling his family since 2001 that he wanted to get out of the military.
The Muslim psychiatrist had told his family he had been taunted after the terrorist attacks of September 11, 2001. Investigations that followed the killings found that he had been communicating via e-mail with Anwar al-Awlaki, the Yemeni-American radical cleric killed by a U.S. drone attack in 2011.
An FBI report in July found that a Joint Terrorism Task Force in San Diego that was investigating al-Awlaki passed two of the messages to another task force in the Washington area, where Hasan was then living. The report found those e-mails should have been passed to the Pentagon -- but the FBI saw no evidence of terrorist activities in his case, believed the information in the e-mails was too sensitive to share and noted that visiting extremist websites is not grounds for taking action.