Steven T. “Duke” Boehle, of Austin, was arrested on April 12 after federal agents and local police searched a residence in that city where three handguns and 1,100 rounds of ammunition were seized.

A second search carried out at a rental storage unit leased by the suspect turned up 10 rifles, according to various media reports.

Boehle wanted to celebrate his 50th birthday on April 13, which he called “Holy Day,” with a mass shooting, an FBI agent testified at a court hearing according to the Austin American-Statesman.

When Boehle was arrested the day before the planned attack, FBI agents found “an expletive-laced note taped to [his] front door that read, ‘The great miracle will take place at 8:30 a.m. on Holy Thursday,’” the newspaper reported.

Currently, Boehle is only charged with making a false statement in connection with the attempted acquisition of a firearm and unlawful possession of a firearm by a prohibited person.

Because of a 1993 conviction for domestic violence in New Haven, Connecticut, he can’t legally possess firearms. Boehle apparently believed those federal firearms laws didn’t apply to him — a cornerstone for sovereign citizens who live in their own make-believe, antigovernment worlds where licensing, laws and regulations are generally ignored.

Boehle hasn’t been charged with any crimes related to what court documents describe as a “mass shooting” plot being investigated by agents assigned to a Joint Terrorism Task Force based in Austin. However, other charges may be in the works.

The suspect’s initial detention hearing was set for April 20, but federal prosecutors asked for and were granted a continuance to May 1. Such delays routinely are sought when federal investigators are building a case for additional charges or are taking the matter to a grand jury for an indictment.

When FBI agents received the “mass shooting” tip earlier this month, they quickly determined Boehle had attempted on “multiple occasions” to purchase firearms from licensed dealers, but was denied because the National Instant Criminal Background Check System (NICS) showed he had a criminal record, court documents say.

During the FBI’s investigation, a confidential informant told agents Boehle “exhibits sovereign citizen extremism ideology, and had recently attempted [again] to purchase a firearm, but was denied,” the documents say.

Boehle had asked the informant to video tape his planned shooting spree, court documents say, but they don’t identify his intended targets.