Salt Lake City police are investigating the roles of two self-described "peacekeepers" following a fatal shooting at Saturday's protest that left one person dead and another injured, raising questions about unauthorized security at public demonstrations.

Utah officials are investigating the role that so-called peacekeepers played in the killing of celebrated fashion designer Arthur Folasa Ah Loo on Saturday at the “No Kings” demonstration in Salt Lake City,

Some 10,000 people gathered in Salt Lake City for a "No Kings" rally and march as President Donald Trump was overseeing a military parade in Washington, D.C. About an hour into the march, shots were fired.