FBI arrests Boogaloo extremist group member in Pomona after gun sales meeting in Murrieta

The FBI quietly arrested a man living in Pomona late last month after he apparently attempted to sell gun attachments to a local group of anti-government extremists to make their firearms more deadly and easier to conceal, according to court documents.

Matthew Edward Chen was arrested on Jan. 28, about a week after he sold three auto sears — devices that can be attached to a firearm to make it fully automatic — to a purported member of the “Cali Bois,” a California-based group that subscribes to an ideology known as “Boogaloo,” an online movement that wants to bring down the U.S. government by encouraging civil war through violent acts.

In court filings, officials said Chen arranged a meet-up with who he believed was a Cali Bois member at a park in Pomona on Jan. 20, where he sold the member the auto sears. What he didn’t know was that the buyer was an undercover FBI agent. Chen then invited the undercover agent to his Pomona apartment, where he allegedly showed the agent more weapons, silencers, and videos of himself firing guns in the desert.

“Chen then returned to the kitchen with a rifle slung around his neck and carrying a Glock semi-automatic handgun. The handgun had a removable stock. The rifle had a removable silencer,” an FBI agent wrote in a criminal complaint filed Jan. 27.

“Chen provided the (undercover agent) with instructions regarding how to install an auto sear on the Glock handgun, and demonstrated how…the handgun would operate as a fully automatic firearm.”

The arrest of Chen — who according to the complaint was himself a member of the Cali Bois who went by the name “Dolphin” in online chats — on a charge of possession of an unregistered firearm, appeared to be part of a larger federal law enforcement effort to disrupt groups of Boogaloo adherents who have inspired violent attacks on government workers and buildings in recent years.

The term “Boogaloo” as it’s used online today emerged around 2013 from groups of internet users espousing violence in the name of protecting certain Constitutional rights, most notably gun ownership, in some of the most extreme imageboards of websites like 4chan and Facebook. Some of these users specifically encouraged others to prepare for a second U.S. Civil War.

Most recently according to the FBI, during the COVID-19 pandemic, “militia violent extremists have made calls for the ‘Boogaloo,’ ‘big igloo,’ or ‘big luau,’ and used imagery such as igloos or Hawaiian shirts to promote their interest or anticipation of an impending war.”

In the complaint, the FBI noted other attacks it believed were inspired by the Boogaloo movement: A 2019 shooting at the Earl Cabell Federal Building in Dallas, in which only the attacker was killed; and two 2020 shootings in Northern California, in which Steven Carrillo, an active-duty U.S. Air Force servicemember, was charged with killing a security guard outside a federal building in Oakland and a Santa Cruz County Sheriff’s Department deputy.

According to the Program on Extremism at George Washington University, which posted the criminal complaint against Chen, at least six Boogaloo members have been arrested in California since 2021, including two who later pleaded guilty to attempting to help Carrillo avoid arrest by federal agents. Around the country, at least 44 people espousing Boogaloo ideology have been arrested in the last two years, according to the program.

For months, at least, the FBI had been tracking the Cali Bois and infiltrating the group in Southern California, according to the complaint.

The undercover agent and an FBI informant attended a meeting with Chen and other Cali Bois members on Oct. 23, 2021, in the Murrieta garage of a member known as “Unicorn,” and referred to as “A.B.” in court documents.

At that meeting, Chen gave a PowerPoint presentation explaining how the members could skirt federal laws governing the building of firearm silencers at home, with one slide entitled “Everything You’re Not Supposed to Know About Suppressors.”

Chen sold at least one silencer to the undercover agent at the meeting for $400, according to the complaint.

He has not been indicted. Chen is expected to return to court in Downtown Los Angeles for a preliminary hearing on Friday.

Chen was released on Feb. 1, after family friends posted $120,000 bond. He was also ordered to surrender his passports and guns, and to have his location tracked by U.S. Marshals through an ankle monitor. He was ordered not to leave the Central District of California.

Court documents showed Chen was living in a short-term rental in Pomona obtained by his father. An FBI agent described Chen as a flight risk because he has dual citizenship and has “evidence of mental problems.” The court ordered Chen to be evaluated by mental health clinicians.

It’s not clear from court documents where Chen was living before relocating to Pomona, or how long he’d been living there.

Federal officials were unable to say Tuesday whether there had been any other arrests of Cali Bois members besides Chen. In the complaint, the FBI said the Cali Bois Boogaloo group “maintains active chapters in, among other places, the greater Los Angeles area, the greater San Francisco and Sacramento area, and the greater San Diego area.”

Court documents did not have more information about any other activities by the group or how the FBI found it in the first place.

A federal public defender assigned to Chen did not return a request for comment Tuesday.