Lt. Gen. John R. Vines, the commander of the Army’s 18th Airborne Corps who signed a document rejecting the plea, retired in February 2007 and could not be reached; messages left with his relatives were not returned. Lawyers for the 18th Airborne Corps, based at Fort Bragg, N.C., whose office advised the general on the Martinez case, also did not respond to e-mail and phone messages.

An Army spokeswoman at Fort Bragg said on Friday that no one with knowledge of the plea offer was available to discuss it.

Maj. John C. Benson, a prosecutor of the Martinez case who was not involved in the decision to reject the plea offer, said there was concern within the Army that Sergeant Martinez might have been eligible for parole after 10 years, despite acknowledging murdering two officers.

“The horrible nature of the crime created a lot of conflict about whether to take the plea,” he said in an interview. But given the outcome at trial, Major Benson said, “I wish that the guilty plea had been accepted,” adding later, “I don’t think there can be any doubt whatsoever as to his guilt.”

Sergeant Martinez’s murder trial was one of only two publicly known cases of enlisted soldiers charged with intentionally killing superiors during the Iraq war. In 2005, Sgt. Hasan K. Akbar of the 101st Airborne Division, was convicted at trial and sentenced to death in a grenade and rifle attack that killed two officers in Kuwait in 2003. General Vines affirmed that sentence in 2006.

In Sergeant Martinez’s trial, prosecutors argued that he detonated a mine on an American base in the Iraqi city of Tikrit, killing his company commander, Capt. Phillip T. Esposito, and Lieutenant Allen in June 2005. Several soldiers from the 42nd Infantry Division, based at Fort Drum, N.Y., testified that Sergeant Martinez hated Captain Esposito and made several threatening statements about him.

Sergeant Martinez’s plea offer, dated April 3, 2006, came after he and his lawyer learned that a soldier had admitted that weeks before the deaths, she had given him Claymore mines that her unit, about to return home, no longer needed. The soldier, Staff Sgt. Amy Harlan of the Army Reserve’s 350th Psychological Operations Company, later testified at Sergeant Martinez’s court-martial.