An Army soldier accused of killing Afghan civilians for sport and encouraging other soldiers to do the same is to go before a military hearing in Washington state.

Staff Sgt. Calvin Gibbs of Billings, Mont., faces charges that include murder, dereliction of duty and trying to impede an investigation. The 25-year-old Gibbs is the highest ranking of five soldiers charged after three civilians were killed during patrols in Kandahar Province this year

Gibbs is to have an Article 32 hearing Tuesday at Joint Base Lewis-McChord south of Seattle. The hearing is similar to a civilian grand jury proceeding, with a military officer determining whether there is enough evidence for a court martial.

Gibbs contends all the deaths were appropriate under combat conditions.