All three served in the same National Guard unit.
When it happened last week, the Army first thought the two officers had been killed by enemy mortar or rocket fire, but an investigation turned up evidence Sgt. Martinez threw grenades into the room Esposito and Allen shared at one of Saddam Hussein's palaces in Tikrit.
The Army said in an announcement that Staff Sgt. Martinez, 37, a supply specialist with the Headquarters and Headquarters Company of the 42nd Infantry Division, was charged Wednesday in connection with the June 7 deaths of the two officers at Forward Operating Base Danger, 80 miles north of Baghdad.
The 42nd Infantry Division is a New York-based National Guard unit.
"Martinez is charged with violation of Article 118 (Murder) with two specifications of premeditated murder," said a statement issued by the Multinational Task Force in Iraq.
It added that "Martinez is currently in pretrial confinement at a military confinement facility in Kuwait."
This is the second instance since the war began of what the military calls "fragging," soldiers killing their officers. If it keeps happening, fragging is an ominous sign of low morale and poor discipline, Martin reports.
The only other fragging occurred more than two years ago, as the 101st Airborne Division was getting ready to cross from Kuwait into Iraq. Sgt. Hasan Akbar used grenades and a rifle to kill two officers and wound 14 others. Akbar, a Muslim who had written his diary "Destroying America is my greatest goal," was convicted and sentenced to death.