FORT BRAGG, N.C. — The court-martial of the first soldier accused of killing a direct superior in Iraq — known as "fragging" during the Vietnam War — opened today, three years after a suspicious blast tore through the living quarters of two National Guard officers.

Numerous delays in the case against Staff Sgt. Alberto B. Martinez have frustrated the widows of Capt. Phillip Esposito and 1st Lt. Louis Allen, both killed when a Claymore mine detonated outside their room in 2005. The trial judge has pledged to hear testimony on holidays and weekends, but the case is still expected to run through the end of the year.

"I never imagined that it would take more than three years to bring him to trial," said Esposito's wife, Siobhan, who along with Allen's wife has attended every hearing. "My life irrevocably changed. In an instant, I became a single parent and had to balance raising our daughter on my own while seeking justice for Phillip's murder."

Martinez, 41, of Troy, N.Y., is accused of planting the anti-personnel mine that detonated on June 7, 2005, in a window just outside the officers' room at Saddam Hussein's Water Palace in Tikrit. The officers died the next day. At an earlier hearing in Kuwait, a witness testified Martinez had said twice that he disliked Esposito and was going to "frag" him.

Defense attorneys have said in court there is no evidence linking Martinez to the killings. They also have said he was charged because of his feud with Esposito, a by-the-book West Point graduate who took over a relaxed National Guard unit. Witnesses have testified the two clashed over the sergeant's performance as supply officer.

The Army reported hundreds of "fragging" incidents between 1969 and 1971, but only four soldiers have been court-martialed or charged with killing a fellow soldier since the Iraq war began in 2003.

"From a military perspective this is a unique case, a soldier attempting to 'frag' his own officers," said Greg Rinckey, an Albany, N.Y., attorney who served as an Army lawyer for six years. "It's a troubling case from a military perspective because it goes to the concept of good order and discipline. This is why the military is seeking the death penalty."

Esposito, 30, of Suffern, N.Y., worked as an information technology manager in Manhattan and was Martinez's company commander. Allen, 34, of Milford, Pa., was a high school science teacher and the company operations officer. The Espositos had a young daughter, and the Allens had four young sons.

Prosecutors also charged Martinez with illegally giving government printers and copiers to an Iraqi, and illegally possessing a firearm, alcohol and explosives. Those charges won't be heard during this court-martial.

Bringing Martinez to trial has been an arduous process, as defense attorneys spent countless hours trying to eliminate a possible death sentence. They won postponements, but failed to escape a capital trial.

The court-martial is taking place at the sprawling North Carolina base because it's where the commander in charge of ground forces in Iraq at the time of the blast was based. The Army has set up a closed-circuit television feed at West Point in New York, but Allen and Esposito's widows are spending thousands to rent apartments and attend the trial in person.

Both women are expected to be among the first witnesses called by prosecutors.

"I can be in the courtroom and represent Lou," Barbara Allen said. "I can work to use this case to teach others what went wrong, and maybe prevent it from happening again. For me that is like finishing Lou's mission for him."