A Marine Corps veteran who authorities said tried to fake his own death after a falling out with a Virginia-based militia group pleaded guilty Wednesday to illegal possession of ricin, a biological toxin.

Russell Richardson Vane IV, 42, of Vienna, Virginia, had been in jail since his arrest in April.

At a plea hearing Wednesday in federal court in Alexandria, Vane admitted that he used castor beans to create ricin at his home.

Ricin is a toxin that occurs naturally in castor beans, and federal law requires anyone in possession of ricin to register and obtain a license.

Vane came to authorities’ attention after an online news outlet reported that a militia group, the Virginia Kekoas, had severed ties with him because they were alarmed by what they considered his loose talk about homemade explosives.

The Kekoas questioned whether he might be a government informant, according to court papers.

Authorities searched Vane’s home and found a plastic bag with castor beans along with a handwritten recipe for extracting ricin, according to an FBI affidavit. Subsequent tests confirmed the presence of ricin.

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At earlier court hearings, Vane’s lawyers argued that prosecutors overstated the danger of Vane’s conduct and said it was virtually impossible for ricin produced in the home to be used as a lethal weapon. They also said that Vane had never threatened anyone.

Prosecutors, though, said Vane’s actions were alarming. They said there is no legitimate reason for an ordinary person to produce ricin, and they also expressed concern about Vane’s efforts to fake his own death. Prosecutors introduced evidence that Vane tried to legally change his name in Fairfax County court and that he posted a fake online obituary of himself.

At Wednesday’s plea hearing, U.S. District Judge Anthony Trenga agreed that Vane could be released until a sentencing hearing set for November. He faces up to five years in prison, but would likely receive far less time. His plea deal does not include any recommended sentence.

A call and email to Vane’s attorney seeking comment were not immediately returned Wednesday evening.