Where defendant is charged with obstructing a peace officer, his conduct must be shown to materially impede the officer, either by causing a material delay in the officer’s performance of his duties or threatening the safety of the officer.The 4th District Appellate Court reversed the decision of McLean County Circuit Judge Scott J. Black.Bloomington Police Officer Mitchell Filarski was monitoring traffic in downtown Bloomington when he claimed he was approached by two men, one of whom was later identified as Landon R …