Staff Sgt . Calvin Gibbs is sentenced to life in prison , with parole possible . NEW : He is under investigation for the 2004 shooting death of a family in Iraq . Gibbs had pleaded not guilty . Prosecutors : Gibbs ' platoon staged killings of civilians as collaboration with Taliban . Defense says Gibbs ' accusers were high on hashish at the time .
Staff Sgt . Calvin Gibbs is sentenced to life in prison , with parole possible . NEW : He is under investigation for the 2004 shooting death of a family in Iraq . Prosecutors : Gibbs ' platoon staged killings of civilians as collaboration with Taliban . Defense says Gibbs ' accusers were high on hashish at the time .