- The widow of Arthur Ah Loo filed a wrongful death lawsuit against local No Kings rally organizers.
- Ah Loo was shot and killed while protesting in Salt Lake City.
- Lawsuit claims negligence by accused gunman Mark Alder and event organizers for inadequate security measures.
SALT LAKE CITY — The widow of the man shot and killed by a so-called "peacekeeper" during the No Kings protest in downtown Salt Lake City last year has filed a wrongful death lawsuit against the accused gunman and organizers of the rally.
On Monday, Laura Ah Loo and her attorneys filed a lawsuit against Matthew Scott Alder — the man who prosecutors say shot and killed her husband, 39-year-old Arthur "Afa" Folasa Ah Loo — and six others who were leaders of the Utah 50501 movement, a grassroots political group that helped organize the June 14, 2025, rally in Salt Lake City.
On that day, police say Arturo Gamboa, 24, assembled and carried an unloaded AR-15 during the large protest in downtown Salt Lake City as an estimated 10,000 people marched on State Street. Two men who police say described themselves as part of a peacekeeping group or "safety team" for the rally spotted Gamboa near 151 S. State.
Fearing that Gamboa was about to commit a mass shooting, Alder, 43, of Murray, allegedly fired three rounds. Although Gamboa was injured, it was the third shot from Alder that hit and killed Ah Loo, a bystander who was marching peacefully, according to charging documents.
Afa Ah Loo "endeavored to be a champion for social justice and firmly believed in Martin Luther King Jr.'s famous phrase, 'Injustice anywhere is a threat to justice everywhere.' As Afa stood filming the protest to share what he viewed as a triumph of the people, he had no idea what was occurring approximately 150 feet south of him," the lawsuit states.
Although Gamboa was arrested, he was later released and no charges were filed against him. After an extended monthslong investigation, Alder was charged with manslaughter, a second-degree felony, and accused of shooting and killing Ah Loo. He was not charged with shooting and injuring Gamboa.
"National 50501 supplied general information, marketing material, and instruction to local groups, including Utah 50501, on best practices for security and de-escalation for an event involving highly charged emotions," according to the lawsuit filed Monday.
The lawsuit names Charles J. Padilla, of Davis County, Travis Hysell, of Utah County, and Collin Catalfamo, Taylor Stapleton and Samantha Cooper, all of Salt Lake County, as leaders of the local 50501 group.
"Based upon belief and information, the leaders, believing that an armed clash with President Trump's supporters was likely, actively supported the arming of Utah 50501 members and the need for armed security at the rally," the lawsuit alleges.
Wendy Garvin, who has experience in organizing large rallies, was contacted to assist with the No Kings rally in Salt Lake City and "communicated with local and state agencies and law enforcement regarding the rally, including planning, security and the possible presence of armed volunteers," according to the lawsuit.
In the days leading up to the rally, the local rally leaders, "in addition to asking its own members to carry concealed weapons, sought additional armed volunteers to act as 'peacekeepers' at the event. Peacekeepers were purportedly selected for their prior law enforcement or military experience; however, based upon belief and information, Utah 50501 and its leaders failed to vet the experience of the volunteers or ensure they had proper training to de-escalate tensions," the lawsuit says.
The group that Alder belongs to was contacted within 24 hours of the No Kings rally for additional security. The lawsuit contends that the rally leaders acted "unreasonably by soliciting individuals to serve as armed security when the rushed timeline meant there was no reasonable expectation that planning or training would be offered before the rally," as well as no time to conduct a proper background check.
On the day of the shooting, "Utah 50501 and its leaders made no attempt to inform the public that it had recruited armed volunteers with little to no training to serve as peacekeepers during the rally," according to the lawsuit.
The lawsuit alleges negligence on the part of Alder, who "with little to no known training in crowd control or de-escalation, failed to clear an area behind Gamboa and instead simply started to fire his gun" when the lawsuit says he "could have walked several feet to the west to ensure he was shooting against a wall and not into a crowd of those he claims he intended to protect."
Furthermore, Alder failed to first approach and talk to Gamboa who was known to carry an unloaded gun during protests.
"As Utah is an open-carry state, Gamboa's carrying of a weapon near a protest, while possibly alarming to some, was not illegal. In fact, a de-escalation manual purportedly used in training by Utah 50501 stated that the presence of a gun in a protest did not mean there was going to be imminent violence. Video surveillance prior to the incident showed Gamboa walking to the west in all black with his gun pointed toward the ground. Despite any obvious or apparent imminent danger, defendant Alder pulled out his pistol and aimed it at Gamboa," the lawsuit alleges.
Laura Ah Loo is also citing negligence on the part of event organizers who had a duty to "ensure that any armed security working for or on their behalf was properly vetted and trained to serve as security and able to de-escalate situations, such as encountering a person with a gun," according to the lawsuit.
Following the shooting, the Salt Lake City Department of Public Lands' Special Events office changed its event permitting application process, which now requires applicants to answer new security-related questions and provide points of contact for events, and the rule adds potential criminal charges for anyone who provides false information on their application.
Monday's lawsuit contends that on June 11, 2025, someone using the name "Michael Andaman" claimed he was part of an organization called "Utah Protest and Rally, LLC" and applied for a permit to march on June 14.
"Because no one has been able to identify Andaman or an actual organization called Utah Protest and Rally, LLC, and because Utah 50501 was the only organization tied to the creation, marketing, advertising and speaker selection for the rally that matched the permit's protest and route description, it is believed and therefore alleged that the permit would have only been sought by or at the behest of the leaders of Utah 50501," the lawsuit states.
The national 50501 movement also disassociated itself with the Utah group following the shooting. Gov. Spencer Cox said organizers were warned against having armed security at the rally.
Laura Ah Loo and her attorneys are holding a press conference to announce their lawsuit.
This story will be updated.
