WASHINGTON — Though the suspect in the shooting rampage at Fort Hood could face the death penalty, he will be prosecuted in a military justice system where no one has been executed in nearly a half-century.

Maj. Nidal Hasan, the Army psychiatrist alleged to have killed 13 people at the massive Army installation in Texas last week, might also benefit from protections the military provides defendants that are greater than those offered in civilian federal courts.

"Our military justice system is not bloodthirsty. That's clear," said Eugene R. Fidell, who teaches military law at Yale.

Much about Hasan's case will be decided by a senior Army officer — perhaps Lt. General Robert Cone, Fort Hood's commander — including whether to seek the death penalty and, in the event Hasan is convicted of capital murder, whether to commute a possible death sentence to life in prison.

Before a military execution can be carried out, the president must personally approve.

George W. Bush signed an execution order last year for a former Army cook who was convicted of multiple rapes and murders in the 1980s, but a federal judge has stayed that order to allow for a new round of appeals in federal court. There hasn't been a military execution since 1961, though five men sit on the military's death row at Fort Leavenworth, Kan.

Federal civilian executions also are rare. Three men, including Oklahoma City bomber Timothy McVeigh, have been killed by lethal injection in federal cases since 2001. Death penalties carried out by states are more common — Tuesday night's execution of John Allen Muhammad in the Washington, D.C., sniper case was Virginia's second of the year.

In the Fort Hood case, Hasan's family has hired a private attorney, John Galligan, although the military also will provide a lawyer at no charge. Galligan said that he and Maj. Christopher E. Martin, Fort Hood's senior defense attorney, spoke with Hasan on Monday and that Hasan had requested a lawyer when first approached by investigators.

Experts in the military justice system said the decision to prosecute Hasan in military court, revealed Monday by officials involved in the investigation, appears clear cut.

The shootings took place on an Army base. The suspect is an Army officer and all but one of those killed also were officers or enlisted personnel. The other person who was killed worked at Fort Hood.

Authorities would have had more reason to take the case to federal court if they had found evidence Hasan acted with the support or training of a terrorist group, but investigators believe he acted alone, without outside direction.