JOINT BASE LEWIS-McCHORD, Wash. (AP) — The soldier accused of killing 16 Afghan civilians watched as child after child described the bloodbath that left their parents and other loved ones dead. Whatever reaction Staff Sgt. Robert Bales might have had, he kept hidden behind a calm face.

Three sessions of overnight testimony in Bales’ preliminary hearing, scheduled to accommodate witnesses participating by video link from Afghanistan, were set to wrap up late Sunday. After the hearing at Joint Base Lewis-McChord, the investigating officer will decide whether to court-martial Bales, who could be sentenced to death if convicted.