A U.S. soldier could face the death penalty after an Army (search) probe recommended Tuesday he be court-martialed in the Iraq war's first case of alleged "fragging," slang for the murder of superior officers.

Staff Sgt. Alberto B. Martinez (search) of Troy, N.Y., had a "personal vendetta" against one of two higher-ranked officers who died in an explosion June 7 on a U.S. base near Tikrit (search), north of Baghdad, military investigator Col. Patrick Reinert said at the end of a two-day hearing in Kuwait.

Reinert said he found "reasonable cause" to believe that Martinez, 37, planted and detonated an anti-personnel mine in the window of a room used by Capt. Philip Esposito, 30, of Suffren, N.Y., and Lt. Louis E. Allen, 34 of Milford, Pa., in a former palace of Saddam Hussein's.

Three hand grenades were also allegedly used in the attack that killed the officers.

Reinert recommended that Martinez face a court-martial hearing and said he found aggravating factors that could allow for capital punishment if the case goes to a military tribunal.

Lt. Gen. John Vines, the commander of the Multi-National Force Iraq, will decide whether there will be a court-martial and where it would be held.

Vines' decision is not expected for several weeks, according to a military legal expert who watched the investigative hearing on a closed-circuit television with reporters on this U.S. military base.

Esposito and Allen were initially thought to have died as result of "indirect fire" on the base, but according to the testimony of Senior Master Sgt. Kevin Fitzgerald, an expert on explosives, fragments of a Claymore mine and parts of three grenades were found in the crime scene.

No clear motive was discussed in the hearing, but legal expert Maj. Matthew Ruzicka said Esposito had relieved Martinez of his supply duties and he was afraid that the measure would affect his civilian job back home.

Capt. Carl Prober, one of nine witnesses who testified in the investigative hearing on Monday, said Martinez told him twice that he hated Esposito and was going to "frag" him. "Frag" is a Vietnam War term for soldiers killing their superiors.

Allen, who was in Esposito's room at the time of the explosion, was apparently in the wrong place at the wrong time. Esposito used his room at the building known as the Winter Palace as living quarters and office.

Reinert recommended that Martinez also be charged with larceny after alleging that the supply officer had illegally obtained the mine and grenades from military stocks.

Martinez's lawyer argued there was no real evidence to tie him to the attack.

Surgeon Col. Joan Sullivan, who tried to save the two officers' lives, told the hearing that the men's injuries were not consistent with wounds caused by a mortar or rocket.

Martinez joined the New York Army National Guard (search) in December 1990. He was deployed to Iraq sometime after October 2004 with the 42nd Infantry.

The Tikrit case is the second during the Iraq war in which a U.S. soldier has been charged with killing his comrades, but it is believed to be the first of an American soldier in Iraq accused of killing his superiors.

In April, a sergeant in the Army's 101st Airborne Division (search), Hasan Akbar, was convicted of murder and attempted murder for a grenade and rifle attack that killed two officers and wounded 14 soldiers in Kuwait in 2003 during the opening days of the war in Iraq.

Akbar, 34, a Muslim, told investigators he carried out the attack because he was upset that American troops would kill fellow Muslims. He was sentenced to death.