A military investigator has recommended that a US soldier face a court martial over charges he murdered two of his superiors while serving in Iraq.
The pre-trial hearing took place at a US army base in Kuwait
Col Patrick Reinert said he had reasonable cause to believe Staff Sgt Alberto Martinez, 38, had killed his colleagues in a personal vendetta.
Speaking after a hearing in Kuwait, he said there were "aggravating factors" which could permit capital punishment.
Defence lawyers for Sgt Martinez said there was no firm evidence against him.
Capt Phillip Esposito, 30, and Lt Louis Allen, 34, died in a blast in Tikrit on 7 June.
The case is believed to be the first in which an American soldier in Iraq is accused of killing his superiors.
Sgt Martinez, who is being held in a military jail in Kuwait, could face the death penalty if found guilty.
Col Reinert's recommendation that he stand trial will be submitted to a senior US commander in Iraq, Lt Gen John Vines, who will make the final decision on whether to hold a court martial.
During the pre-trial hearing, nine prosecution witnesses were questioned at the US-run Camp Arifjan, south of the capital Kuwait City.
A day later, Col Reinert said he had "reasonable cause" to believe that Sgt Martinez had used an anti-personnel mine and three grenades to kill his superiors.
Capt Esposito and Lt Allen died in a blast in a former palace of Saddam Hussein, which was being used as a base.
An initial investigation indicated that the officers were killed in a mortar attack.
The explosions were later ruled not to be mortar attacks, witnesses told the hearing on Monday.
Another witness testified that the defendant told him he wanted to kill one of the victims.
Defence lawyers challenged the charges as mere "arguments and speculations".