Capt. John Buck disobeyed a direct order last October when he refused a to take the anthrax vaccine before deployment overseas, a court-martial panel ruled Monday.

The ruling came about 30 minutes after the panel, made up of 11 of Buck's fellow officers at Keesler Air Force Base, received the case.

Buck had entered an innocent plea to the charge Friday.

Buck gave no reaction as the verdict was read, remaining stoic as he has been throughout the weeklong proceedings.

Sentencing is scheduled for Tuesday. Buck faces up to five years in prison, dismissal from the Air Force and a total forfeiture of pay and allowances.

Belinda Bazinet, a spokeswoman for Keesler AFB, said Buck could escape with no punishment if the panel sees fit.

"They (the panel) are not obligated to put any punishment in place," she said.

The proceedings deal with Buck's refusal to take the vaccine, not with safety and health issues surrounding the drug.

Military prosecutors presented a brief case Monday.

The panel heard from Buck's commanding officer, the former commander of the medical readiness group at Keesler, the officer who selected Buck for overseas deployment and the medical technician who would have given him the vaccine.

Buck offered no defense.

Last week, Lt. Col. Mark Allred, the presiding military judge, rejected the primary defense argument -- that the anthrax vaccine is an experimental and potentially hazardous drug unlawfully forced on soldiers.

Earlier Monday, Buck, 32, was told a conditional resignation request he had submitted after Allred's ruling had been rejected.

The emergency room physician had wanted no less than a general discharge, a separation from the Air Force one step lower than an honorable discharge.

Brig Gen. Roosevelt Mercer Jr., the wing commander at Keesler and Buck's commander, returned the conditional resignation to Buck, Bazinet told The Sun Herald newspaper.

Under military rules, when conditions are placed on a resignation request, the commanding officer has the right to reject it.

Mercer said he felt the request inappropriately limited the Secretary of the Air Force's ability to act in Buck's case. He said the Air Force should be given the full range of options when dealing with any resignation request.

Buck later said he was unsure whether he would now submit an unconditional resignation request to the Air Force.

The panel selected to hear the court-martial ranged in rank from captain to colonel.

There was no word from the office of U.S. Sen. Trent Lott, R-Miss., on whether the senator had reviewed a request from Buck to get involved in the case.

A number of coast residents supporting the physician also petitioned Lott to ask the secretary of the Air Force to allow Buck to resign.

"All branches of the military have had problems with retention and recruiting," Buck said in a letter to Lott dated last Friday. "It would not be in the best interest of all parties to convict a physician for legitimate professional concerns. A resignation allows both sides to part amicably."