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.
The two men, who were wearing yellow “high visibility” vests during the incident, were questioned and released as investigators work to determine whether they were appointed by protest organizers, volunteered or were self-appointed.
Neither individual has current or former law enforcement experience, according to the Salt Lake City Police Department (SLCPD).
The incident occurred during a “No Kings Day” protest that drew an estimated 10,000 people to Pioneer Park. According to Salt Lake City Police, the violence erupted when two men, identified as “peacekeepers” by police, confronted 24-year-old Arturo Roberto Gamboa after spotting him allegedly pulling out and “manipulating” a rifle near 151 S. State Street around 8 p.m.
Demonstrators carry signs and chant while marching during a “No Kings” protest, June 14, 2025, in Salt Lake City.
Amanda Barrett/AP
“Witnesses say Gamboa raised the weapon in a firing position and began running toward the crowd,” Salt Lake City Police Chief Brian Redd said Sunday at a news conference.
One of the peacekeepers opened fire, striking both Gamboa and an innocent bystander, Arthur Folasa “Afa” Ah Loo, 39. Ah Loo was killed in the incident, while Gamboa was wounded and later arrested, according to police.
The protest was organized by 50501, a grassroots political group known for organizing rallies and protests nationwide.
According to police, there was no record in the event’s permit indicating the presence of organized or armed security, and investigators are still working to determine the total number of “peacekeepers” present at the rally.
The shooting prompted a swift reaction from state leadership. Utah Gov. Spencer Cox called the incident “a deeply troubling act of violence” that “has no place in our public square” in a statement Saturday night. After speaking with Salt Lake City Mayor Erin Mendenhall, Cox later posted on X: “My heart is broken for everyone impacted tonight.”
While Utah law allows for firearm possession and use under certain circumstances, police say the legality of any individual’s actions will depend on the specific details of the case.
The SLCPD’s homicide detectives are working with the Salt Lake County District Attorney’s Office to determine if the use of deadly force was lawful under state law.
Police say Gamboa, who was found “crouching down among a small crowd of people” after the shooting, was dressed in black clothing and a mask, and possessed an AR-15 style rifle, a gas mask, and a backpack. He has been booked into the Salt Lake County Jail for investigation of murder, though police confirm he did not fire any shots.
The protest in Salt Lake City was part of nationwide “No Kings Day” demonstrations that drew over 5 million participants across the country, according to organizers. The protests were held to counter the Trump administration and a military parade in Washington, D.C.
The investigation remains ongoing, with SLCPD homicide detectives working closely with the Salt Lake County District Attorney’s Office. The department has requested that anyone with photos or videos of the incident upload them to their evidence portal.
“Our detectives are now working to thoroughly investigate the circumstances surrounding this incident,” Redd said in a press release. “We will not allow this individual act to create fear in our community.”
