Attending the protests for the first time over the weekend was Christopher David, 53, a former Navy civil engineering corps officer and a 1988 graduate of the U.S. Naval Academy…

He had taken a bus to the Portland courthouse and was about to leave around 10:45 p.m. when federal officers emerged and began advancing on the protesters. He said he felt the need to ask the officers, Why were they violating their oath to the Constitution?

Instead of getting an answer on Saturday, Mr. David, a 6-foot-2, 280-pound former Navy varsity wrestler, found himself being beaten with a baton by a federal officer dressed in camouflage fatigues as another doused him with pepper spray, according to video of the encounter.

Mr. David was taken to a nearby hospital, where a specialist said his right hand was broken and would require surgery to install pins, screws and plates.