One of the seven US marines facing charges related to the killings of 24 Iraqi civilians in Haditha two years ago has admitted to lying about the deaths of five of them.
Sergeant Sanick Dela Cruz, 24, said he saw Sergeant Frank Wuterich, his squad leader in Haditha, shoot dead five men while they had their hands up to surrender.
Cruz, who was granted immunity from prosecution, also admitted to urinating on one of the dead bodies after a squad member was killed in a roadside bombing.
Wuterich is facing multiple murder charges.
Cruz was testifying in a preliminary hearing on Wednesday into charges against Captain Randy Stone, who is accused of failing in his duty to investigate and report the 24 deaths.
Cruz said he also pumped bullets into the five dead men before Wuterich shot them again in the torso and head, and told him to blame the Iraqi army.
"I just held my weapon up and shot them. I know they're dead, but I wanted to make sure they were dead," he told the hearing.
Cruz said he agreed to go along with Wuterich's story because he was "trying to cover up [for] the squad".
But his testimony had no direct link to Stone.
The preliminary hearing will determine whether Stone's case advances to a full court-martial later this year.
Prosecutors allege marines patrolling Haditha were angered by a comrade's death and had gone on a shooting rampage against unarmed men, women and children.
Three of the marines are facing murder charges while four others have been charged with a cover-up.
All seven accused said they were following orders.