A California man wanted on charges of plotting murders for white supremacist gangs was found dead in a Costa Rican jail cell within hours of being captured, prosecutors revealed Monday.

Matthew “Cyco” Hall, 48, of Orange County, had been a federal fugitive since June, when he was indicted in a huge racketeering case centered on the Aryan Brotherhood prison gang. Hall was accused of being affiliated with the Aryan Brotherhood and being a member of a skinhead street gang known as Public Enemy No. 1, or PENI.

At a June press conference announcing the case, authorities vowed to arrest Hall, saying he was believed to be out of the country.

Court records filed by the U.S. Attorney’s office Monday say that Hall was arrested Sept. 27 in Jacó, a Costa Rican city on the Pacific Coast, with a population of about 10,000. Hours after being detained and booked into a local jail, Hall hanged himself, according to public records.

A prosecution motion filed Monday includes Hall’s death certificate, in Spanish, which lists the cause of death as asphyxia by hanging.

Videos of Hall announcing his allegiance to PENI, and self-proclaimed status as a “neo-Nazi” have surfaced online. In some, Hall vowed he wouldn’t go peacefully if the police came to arrest him, and pledged to get into a shootout with police if need be. One video shows Hall sitting on a couch, holding a pistol that he says will “blow a Glock in two pieces.”

“It will also dump anything or anybody like a sack of (expletive) potatoes, including every one of you (expletive) pigs that thinks he’s gonna come over to my (expletive) house and I’m just gonna (expletive) cuff up,” Hall says, sneering into the camera. “The hunters are now the (expletive) hunted.”

In another portion of the roughly 45-second video, Hall identifies himself by name and his nickname, “Cyco,” and says he’s a member of “PENI Death Squad.” The date the video was taken is unknown.

“I am white power. Neo-Nazi National Socialist (expletive) skinhead,” Hall says, later adding: “You (expletives) wanna give me 38 to life for nothing? … I’m gonna take it to you, and you better come (expletive) deep and you better tell the rookies to stay back. … I’m gonna cut your cars in half with AK-47s and I’m gonna sabotage you (expletive).”

In July, federal prosecutors indicted Hall in one of four cases against more than two dozen alleged Aryan Brotherhood members and associates. The evidence against him, according to the complaint, was based upon wiretapped conversations between Hall and one of the Aryan Brotherhood’s leaders, a Pinole native named Ronald Dean Yandell, also known as “Renegade.”

Yandell, serving life in prison for convictions of manslaughter and murder, acquired several contraband cellphones. In phone calls, he allegedly directed Hall to sell heroin to other gang affiliates and discussed ongoing murder plots in Southern California. This included an alleged plan to kill another Aryan Brotherhood member, Michael “Thumper” Trippe, of San Diego, prosecutors said.

In another call, Yandell is accused of telling Hall he would soon pave the way for Hall to be made a member of the Aryan Brotherhood, and that final approval was “just a formality.”

Three years before the indictment was filed, Hall was implicated in a July 2016 robbery at an Orange County hotel that took a deadly turn. It involved Irvine resident Daniel “Shakey” Richardson, an alleged drug dealer who was shot and killed while trying to rob another meth dealer, allegedly on behalf of the PENI gang, according to court records. Two of Richardson’s accomplices made off with money and property.

Hall was accused of setting up the robbery to collect a $2,500 Aryan Brotherhood debt, but was freed after a judge threw out conspiracy to commit extortion charges against him. In late 2018, a California appeals court reversed the dismissal, allowing prosecutors to refile the case against Hall, but by that point, he was in hiding.

According to prosecutors, Yandell ruefully talked about the botched robbery on wiretapped calls, saying that Hall being out of custody was a valuable resource for the Aryan Brotherhood. Yandell reportedly blamed another Aryan Brotherhood member, Kenneth “Kenwood” Johnson, for Hall being implicated in the robbery, and instructed Hall not to give Johnson any of the proceeds.

Yandell also allegedly arranged for Hall to give heroin to Jeanna Quesenberry, described by police as a member of another Aryan Brotherhood-affiliated street gang, the Family Affiliated Irish Mafia, or FAIM. During their meeting, Hall told Quesenberry he had served time with Yandell in Pelican Bay State Prison, describing himself as a “shot caller,” or high-ranking prison gang member, according to the criminal complaint.

Hall told Quesenberry he was willing to kill for Yandell, adding that he was armed and “was a true racist and a true gangster,” according to the complaint. In September 2016, when authorities raided his Hermosa Beach home, they found six guns, Nazi propaganda, videos about Adolf Hitler and a jacket containing Nazi symbolism with Hall’s nickname, “Cyco,” and the words “PENI Death Squad,” prosecutors said.