(Portland, OR) -- A Portland man is pleading guilty to assaulting a federal officer outside of the ICE building. Last June, 25-year-old Robert Hoopes threw a large rock and hit an ICE agent in the head, causing a significant laceration. Hoopes also used a stop sign as a battering ram to damage the entry door to the building. Hoopes was indicted by a federal grand jury and pleaded guilty to aggravated assault of a federal employee with a dangerous weapon resulting in injury. He'll be sentenced in May.