Salt Lake City, UT — A protest in downtown Salt Lake City turned deadly Saturday evening when a designated private peacekeeper opened fire after confronting an armed individual, unintentionally killing a bystander.

The suspect, 24-year-old Arturo Gamboa, a Utah resident with no prior criminal history, has been arrested and charged with murder.

According to Salt Lake City Police Chief Brian Redd, the incident occurred around 8:00 p.m. near 100 South and 200 East during a “No Kings Day” demonstration.

Officers from the department’s Motor Squad were on duty nearby when they heard gunfire. Responding officers arrived on the scene and found 39-year-old Arthur Folasa Ah Loo lying on the ground with a gunshot wound.

Despite emergency aid from SWAT medics and paramedics, Ah Loo was later pronounced dead at a local hospital.

Authorities say the situation escalated when Gamboa, armed with an AR-15-style rifle, was observed by two individuals believed to be private armed security assigned to monitor the protest.

Witnesses reported that Gamboa had separated himself from the crowd and concealed himself briefly behind a wall before emerging with the weapon.

Gamboa then raised the rifle into a firing position and began moving toward the crowd.

One of the peacekeepers, fearing an imminent threat, fired three rounds from a handgun.

One round struck Gamboa in the left side of his abdomen, and another tragically hit Ah Loo, an uninvolved and peaceful protest participant.

Gamboa, though wounded, attempted to flee by blending back into the crowd. Bystanders quickly pointed him out to police officers, who arrested him without further incident.

During his apprehension, officers recovered the AR-15-style rifle, a gas mask, and a backpack in Gamboa’s possession.

Investigators later confirmed that Gamboa never fired his weapon.

All shots were discharged by the security personnel. However, under Utah law — consistent with legal principles in many jurisdictions — an individual can be charged with murder if their criminal actions create circumstances that directly result in someone’s death.

Salt Lake City Police are actively working with the District Attorney’s Office to review the case and determine if further charges will be pursued.

The police department has not commented on whether prior tips about a man carrying an assault-style weapon inside a local Maverik convenience store, as mentioned in witness Facebook videos, are substantiated.

The incident remains under thorough investigation.

Authorities have asked anyone with video or information related to the shooting to contact law enforcement.