to be a detonator. facebook, soon, cut off his live stream and law enforcement surged in. setting up a wide perimeter and evacuating several nearby buildings, including the supreme court and a house office building. roseberry communicated with police at first using a dry erase board. at one point writing, don't shoot me. police, eventually, sent in a robot with a phone to communicate more clearly but he never used it. surrendering, instead. >> right now, we have no indication that he was acting with -- with anyone -- anyone else. but that, again, is part of the ongoing investigation. >> reporter: capitol police said, later, they found possible bomb-making materials inside the truck. but not a working bomb. the standoff marked the third major security incident on capitol hill this year. following the deadly january-6th insurrection and a good friday incident in which a man rammed a security barrier, killing a capitol police officer. the standoff drawing an outpouring of support online for the capitol police from lawmakers. including hawaii's senator, brian schatz, who tweeted they