CAMP PENDLETON – A Marine has pleaded not guilty to charges of unpremeditated murder and dereliction of duty in the slaying of an unarmed detainee in Iraq nearly four years ago.

Sgt. Ryan Weemer of Hindsboro, Ill., entered the plea during a brief appearance Monday in a Camp Pendleton courtroom.

Weemer appeared about 72 hours after he and a co-defendant, Sgt. Jermaine Nelson, told a federal judge in Riverside they would not testify against a third man charged in the killing, former Marine Sgt. Jose Nazario Jr.

Nazario is on trial in federal court for voluntary manslaughter and for directing Weemer and Nelson to take part in the November 2004 killings in Fallujah.