In recent weeks, communities in central Texas have been dealing with a spreading plague of neo-Nazi organizing and vandalism, culminating in an arson attack on an Austin synagogue. But thanks to some sleuthing work by Austin Fire Department’s arson squad, investigators were able to track down and arrest the alleged perpetrator this week.

Franklin Barrett Sechriest, 18, of nearby San Marcos was arrested Wednesday on suspicion of arson, a first-degree felony, after the exterior of the Congregation Beth Israel was torched on Halloween. An affidavit filed in the case said that Sechriest was identified after security cameras caught images of the black SUV he drove to commit the arson—and its license plates.

Journalist Nate Thayer identified Sechriest as a member of the Goyim Defense League, a California-based neo-Nazi organization whose members have been cruising central Texas in recent weeks spreading propaganda—including dropping freeway banners with antisemitic slogans, posting antisemitic fliers around communities, and dropping them in plastic bags on people’s lawns in local neighborhoods, including in San Marcos. However, authorities have not confirmed that connection, and GDL’s leader denies any association with him.

Franklin Barrett Sechriest’s mug shot after his arrest in a recent synagogue arson in Austin.

According to the affidavit, investigators were able to identify Sechriest after reviewing multiple videos from surveillance cameras in the area of the synagogue. They showed a masked man in a black T-shirt who parked a Jeep in its parking lot and got out with a green fuel canister walking toward the area where the fire started; then, as flames break out, he can be seen running back to the SUV and fleeing.

Additional video from three nights beforehand showed the same SUV surveilling the synagogue, with the suspect shining a light into its Child Development center after he hit a curb. Those images clearly show his license plate—a vehicle registered to Sechriest.

The synagogue fire was quickly extinguished, and its members expressed relief that the harm had been minimal, causing some $25,000 in damage. The next day, community leaders organized a rally denouncing the attack, featuring two dozen faith leaders and clergy members from across Austin.

“Hateful acts of intimidation to incite violence is unacceptable, and we will not be silent,” Simone Talma Flowers, the executive director of Interfaith Action of Central Texas, said at a press conference. “We stand united with our Jewish community as they are targeted and victimized by acts of antisemitism.”

The arson attack was the most violent of a string of antisemitic hate incidents that had beset central Texas in recent months, much of it the work of the Goyim Defense League. The latter had organized a banner drop on Oct. 23 in Austin, when about a dozen people displayed a banner targeting Jewish people at an overpass on North MoPac Expressway that featured the URL to the group’s website.

The fliers promoting a neo-Nazi group, distributed in San Marcos, Texas.

The same group also scattered fliers around the Willow Creek neighborhood in San Marcos in plastic bags weighed down with gravel. Melanie Liddle told the Texas Tribune that she discovered one of them in her driveway, and said the fliers had appeared in every driveway on her street. She said a police officer told her that more than 200 such flyers had been collected.

“I call this hate speech,” Liddle added. “To me, this is threatening our Jewish neighbors.”

Jewish leaders in San Marcos were concerned. “Someone called me and left me a voicemail. They were quite upset. They lived in the neighborhood where she herself got the flier, a member of the Jewish community,” said Rabbi Ari Weingarten, Director of Rohr Chabad. “Then [the messages] didn’t stop coming. Another email somebody said that their stepson received the flier from this individual. So, I heard about it [Saturday] and it was quite frustrating and upsetting, disturbing.”

GDL also organized a crudely antisemitic protest outside of a fundraiser for Israel held in San Antonio, and the next door organized a similar protest outside the Jewish community center there. Two neighborhoods in that city also were hit with antisemitic GDL fliers left on lawns.

On Oct. 22, someone painted swastikas and homophobic slurs in the parking lot at Austin’s Anderson High School. It’s unclear if that incident was connected to any organized group.

The Anti-Defamation League explains that the GDL is a very small group of intensely dedicated neo-Nazis from around the country who organize attention-grabbing stunts and post them online, earning them thousands of followers. Its primary organizer is a Petaluma, California, man named Jon Minadeo II, who created his own video and media platform, GoyimTV, after he was booted from YouTube.

GoyimTV features almost exclusively antisemitic and other neo-Nazi content, including livestreams and podcasts. Minadeo and his cohorts proudly posted their antics in Texas throughout their tour there, including video of the men lighting a swastika on the ground the same night as the synagogue fire and saluting it, uttering various neo-Nazi slogans.

Thayer identified one of those men around the burning swastika as Sechriest. However, that person’s face was masked, although the shirt he is wearing may be a match for the one worn by the arsonist and captured in surveillance video. Investigators are being mum about Sechriest’s background, however.

Minadeo, meanwhile, vehemently denied to The Daily Beast that Sechriest was associated with GDL. In a tense phone conversation, he claimed the group doesn’t condone violence: “We’ve never, ever done anything violent towards Jews,” Minadeo said, insisting that the flaming swastika they saluted the same night was just “burning the flag of what we believe is the synagogue of Satan.”