CNN Newsource
Originally Published: 04 DEC 25 11:52 ET
By Nate Carlisle
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SALT LAKE CITY (KSTU) — Nearly six months after a fatal shooting on the streets of Salt Lake City during this summer’s No Kings protest march, criminal charges have been filed against the event volunteer connected to the deadly incident.
Salt Lake County District Attorney Sim Gill announced Wednesday that his office has filed second degree felony manslaughter charges against Matthew Alder, the man who was serving as a so-called “peacekeeper” during the June 14 downtown rally and march.
As thousands of people marched downtown following the rally, Alder fired his weapon at a man seen holding an AR-15 rifle. The ensuing gunfire struck fashion designer Afa Ah Loo, a bystander who was attending the event and was hit near 151 South State Street. Ah Loo was transported to a nearby hospital, where he later died.
A summons has been issued for Alder, who Gill said has been cooperating with the investigation and is not considered to be a flight risk.
Despite detectives finding a disassembled AR-15, three loaded magazines and a knife on the man carrying the rifle, identified as Arturo Gamboa, he will not be charged.
Another security team member told police they had seen Gamboa “hide” behind a column and appear to pull out part of the rifle, and “was struggling” to put it together. The witness added that he understood Utah’s open carry laws, but felt the situation involving Gamboa was different, as he was “assembling [the rifle] under cover.
Alder’s fellow security team member then called out “gun, gun, gun” over his radio as Gamboa moved towards State Street, and believed he was “about to commit a mass shooting,” the indictment states. The unidentified witness added that he “should have dropped him,” regarding Gamboa, but said he did not have a shot and told police, “there’s no way I can shoot [Gamboa] when he’s running toward a crowd.”
It was at that point that the witness said Alder, who was standing on his left, fired at Gamboa with a 9mm handgun.
Days after the shooting, Alder told detectives that he believed Gamboa was “psyching himself up” and looked to be in “combat mode.”
“Oh, my God, this is happening, this is really bad, somebody’s going to get hurt,” Alder told detectives he thought to himself at the time.
After firing the first time, Alder claimed Gamboa continued to move towards the crowd and ordered him to get on the ground. Alder said he fired two more times when Gamboa allegedly moved his rifle up from a “lower position.”
Alder told detectives that when he fired two more times, he thought, “If I have to fire, I please God, don’t let me have to fire but I want people to be as safe as I can.”
The third bullet fired by Alder is believed to be the one that struck Ah Loo.
Once shots were fired, video surveillance showed Gamboa fleeing the scene and entering a parking garage where he placed his rifle into a backpack.
“Although Mr. Gamboa engaged in what could reasonably be perceived as alarming and irresponsible conduct by assembling an AR-15 under cover during a mass gathering, he was lawfully permitted to carry the rifle in a concealed and subsequently open manner under existing Utah law,” Gill said.
Alder had been hired by SLC 50501, the group that organized the local protest. and was not a law enforcement officer or associated with the Salt Lake City Police Department, but was a military veteran.
According to Salt Lake City Police, the event permit filed by SLC 50501 did not indicate the presence of organized or armed security at the protest.
Attorney Mitch Vilos has written multiple books on Utah’s gun laws. He does not represent anyone connected to the No Kings shooting, but doesn’t believe Alder will be convicted.
“You’re looking at a potential mass shooting, is what I believe his reasonable belief was. He doesn’t have any criminal intent. His intent is to be a defender,” Vilos said.
Gill explained how his office relied, in part, on a recent court ruling in Massachusetts with similar circumstances that led him to file charges in Utah.
“Utah courts are not bound by anything that Massachusetts does, and shouldn’t be, because their philosophy is totally different,” Vilos said. “They have a duty to retreat before they can use deadly force in Massachusetts.”
After the shooting, a guidebook on the website of the national 50501 organization stated its peacekeepers should have strong situational awareness, the ability to remain calm under pressure, knowledge of de-escalation strategies and protest safety, as well as good communication and teamwork skills.
At the time, the guidebook added that peacekeepers are “not expected to confront or disarm someone with a weapon — though peacekeepers have in dire situations.”
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A local resident holds a sign during a small gathering of protesters at Lafayette High School on Thursday in St. Joseph. 
