FORT CAMPBELL, Ky. — A 101st Airborne Division soldier was sentenced yesterday to 18 years in prison for murdering a detainee and taking part in the killings of two others in Iraq last year.

Private First Class Corey Clagett, 22, was one of four soldiers from the division’s 3rd Brigade “Rakkasans” who were accused in the detainees’ deaths during a May 9 raid on the Muthana chemical complex in Samarra, about 60 miles north of Baghdad.

In an agreement with prosecutors, Clagett, of Moncks Corner, S.C., pleaded guilty to charges of murder, attempted murder, conspiracy to commit murder, and conspiracy to obstruct justice. Prosecutors dropped a second obstruction charge and charges of disrespecting an officer and threatening.

The soldiers first told investigators that they shot the detainees because they were attempting to flee — a story they now say they made up — and that commanders had given them orders to kill all military-age males on the mission.

Two of those soldiers, Specialist William Hunsaker and Specialist Juston Graber, have changed their stories and pleaded guilty. The squad leader, Staff Sergeant Raymond Girouard, is awaiting his court-martial.

Sergeant Girouard “said we were going to cut the zip ties loose and kill the detainees,” Clagett told the judge, Colonel Theodore Dixon, yesterday. “I knew it was an unlawful order. I just went along with it.”

Prosecutors said Clagett fatally shot one detainee and seriously wounded another. Official say Graber then killed the wounded detainee, and Hunsaker killed the third. The judge asked Clagett what his intention was when he shot at the detainees.

“To kill them, your honor,” Clagett said.