[JURIST] Staff Sergeant Robert Stevens pleaded guilty on Wednesday to shooting two unarmed Afghan farmers at a trial held at Joint Base Lewis-McChord [official website]. Stevens pleaded guilty [Reuters report] to aggravated assault with a dangerous weapon, wrongfully tossing a grenade out of his vehicle, making false statements to military investigators and dereliction of duty. He did not plead guilty to a fifth charge of conspiracy to commit assault. Military prosecutors originally sought a prison term of 18 months, but…