(Raleigh, North Carolina) A U.S. National Guardsman who pleaded guilty to killing a 17-year-old Iraqi said he shot the young man 11 times after they had sex in a guard tower, a North Carolina newspaper reports, citing court-martial records.

Pte. Federico Daniel Merida, 21, pleaded guilty to murder without premeditation and other charges during a court martial in Iraq in September.

Merida was sentenced Sept. 25 to 25 years in prison and reduced in rank and will be dishonorably discharged. He is being held at Fort Leavenworth, Kan., a Leavenworth spokeswoman said.

U.S. army officials at Forward Operating Base Danger, where the court martial was held in Iraq, had withheld details of the case.

However, the News & Observer newspaper of Raleigh reported on the weekend that records said Merida and the Iraqi were on guard duty May 11 in a tower on the perimeter of an army camp near Tikrit in northern Iraq. At about 10:30 p.m. local time, Merida shot the teen 11 times with his carbine.

Merida first told investigators the teen demanded money at gunpoint. Later, he said he killed the boy because he forced him to have sex. In a third interview, Merida said he was angry after the two had consensual sex.