A man in Florida who shot two of his roommates dead gave an unusual defense, the authorities say: they were neo-Nazis who had disrespected his recent conversion to Islam.
The arrest of the gunman, who said he had also been a neo-Nazi before becoming Muslim, led to the discovery that a fourth roommate had been stockpiling materials that could be used to create a bomb, according to a federal criminal complaint. That roommate, a member of the Florida National Guard, kept a picture of Timothy McVeigh, the Oklahoma City bomber, on his dresser, the authorities said.
Both men are now in custody. The accused gunman, Devon Arthurs, 18, has been charged with two counts of murder, and his surviving roommate, Brandon Russell, 21, has been charged with two counts related to the explosive material and devices.
Authorities first became involved on Friday evening when Mr. Arthurs took three people hostage at gunpoint at a head shop in Tampa, according to an affidavit from the Tampa Police. He was arrested soon after.
The police said Mr. Arthurs told his hostages that he had killed someone and that he was furious over American bombings of Muslim countries; he was convinced by police officers responding to the incident to let the hostages leave and to surrender.
He then told the officers that two of his roommates were dead, according to the affidavit, and guided the police to the apartment where they found the bodies of the two roommates, Jeremy Himmelman, 22, and Andrew Oneschuk, 18. The fourth roommate, Mr. Russell, was standing outside the apartment crying and wearing “full U.S. Army camouflage.”
Later, Mr. Arthurs confessed to shooting Mr. Himmelman and Mr. Oneschuk, describing the weapon he had used and other key details. He said that all four roommates had been friends, “with a common neo-Nazi belief,” until Mr. Arthurs’s recent conversion to Islam, according to the affidavit.
“Since then, Arthurs stated, he has become angered by the world’s anti-Muslim sentiment,” the affidavit says, adding, “Arthurs also stated that, prior to the murder, he had been privy to neo-Nazi internet chat sites threatening to kill people and he had developed a thinking that he should take some of the neo-Nazis with him.”
Lyssa Himmelman, a sister of Jeremy Himmelman, told the Tampa Bay Times that neither her brother nor Mr. Oneschuk were neo-Nazis, as Mr. Arthurs claimed.
According to a federal criminal complaint, Mr. Arthurs also told the police that Mr. Russell, in whose room officers found Nazi and white supremacist propaganda, had, in chat rooms, “threatened to kill people and bomb infrastructure.”
A search of a garage below the apartment on Friday and early Saturday morning led to the discovery of “a white-cake-like substance” that federal and police technicians recognized as an explosive, as well as other substances and parts that could be used to detonate explosives, including ammonium nitrate contained in a package addressed to Mr. Russell.
Mr. Russell, who was arrested on Sunday in Key Largo, confirmed to law enforcement officials that he was member of Atomwaffen, a neo-Nazi group, and that he had manufactured the “white-cake-like substance,” the authorities said. He told the F.B.I. that he had been planning to use the substance to “boost homemade rockets and to send balloons into the atmosphere for testing.” The F.B.I. agent who wrote the affidavit on which the complaint was based, Timothy A. Swanson, expressed skepticism about Mr. Russell’s explanation, given the volatility of the substance.
An F.B.I. spokeswoman declined to explain why Mr. Russell had been allowed to go to Key Largo, which is about five hours away from Tampa, or what he had been doing there, citing the active nature of the investigation.
The Southern Poverty Law Center identifies the Atomwaffen Division as an active neo-Nazi hate group, and the Anti-Defamation League, in a blog post in December, said that the group was particularly active on college campuses.