SALT LAKE CITY (AP) — A military veteran who was trying to stop an alleged gunman and inadvertently shot and killed a demonstrator at a Salt Lake City “No Kings” rally was a “safety volunteer” for the demonstration, according to police and organizers.

An innocent bystander at a “No Kings” protest in Utah was shot and killed by a “peacekeeper” who was aiming for a different man pointing an AR-15-style rifle toward the crowd, witnesses told Salt Lake City police.

The alleged rifleman, Arturo Gamboa, 24, was also shot and was taken into custody on a murder charge, Salt Lake City Police Chief Brian Redd said at a Sunday news conference. The bystander who was killed was identified as Arthur Folasa Ah Loo, 39, a fashion designer from Samoa.