The FBI has charged a Colorado white supremacist in a plot to blow up a Pueblo synagogue, according to recently unsealed federal documents.

An affidavit filed Saturday in U.S. District Court in Colorado says that on Friday, Richard Holzer met with an undercover agent, bringing explosives he intended to use on Temple Emanuel with him.

The undercover agent mentioned the prospect of congregants being inside the building when the bomb detonated. In response, “Holzer stated that he did not think anyone would be there, but that if they were, Holzer would not care because they would be Jews,” the affidavit said.

The affidavit also states that an undercover agent had communicated with Holzer through Facebook beginning in late September, where Holzer told them he was an ex-Ku Klux Klan member and currently a racist skinhead.

Holzer used several accounts through the social media platform to discuss and threaten several acts of violence, according to the affidavit. On July 11, he sent a message saying he was “getting ready to cap people” accompanied with a photo of him wearing clothing featuring white supremacist symbols and aiming a long gun.

He also allegedly told an undercover agent that he had paid a Mexican man he called “Mexican Hitler” $70 to “hex and poison a local synagogue” and that he had put arsenic in the synagogue’s water pipes on Oct. 31, 2018.

Holzer later told the agent he planned to poison Temple Emanuel again in advance of a race war he was preparing for, according to the affidavit. Authorities have charged him with attempting to obstruct a religious exercise by force using explosives and fire.