One of four US soldiers accused of raping a 14-year-old Iraqi girl last spring and killing her and her family pleaded guilty and agreed to testify against the others. Spc. James P. Barker agreed to the plea deal Wednesday to avoid the death penalty, said his civilian attorney, David Sheldon. The military judge presiding over the case, Lt. Col. Richard Anderson, asked Barker why he participated in the attack in Mahmoudiya, a village about 20 miles (32 kilometers) south of Baghdad. It was among the worst in a series of alleged attacks on civilians and other abuses by military personnel in Iraq.