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May 23, 2017, 12:27 AM UTC / Updated May 23, 2017, 12:27 AM UTC

A former neo-Nazi who converted to Islam was charged with killing two roommates in his Florida apartment after he says they disrespected his faith, authorities said.

Devon Arthurs, 18, was booked on two counts of first-degree murder, two counts of aggravated assault and three counts of armed kidnapping, jail records show.

Devon Arthurs is shown in this mugshot released by the Tampa Police Department. Tampa Police Department

Cops first encountered Arthurs Friday afternoon after he took hostages at a smoke shop north of the city, according to a statement from a Tampa Bay police spokesperson.

Arthurs barred an employee and two customers from leaving the shop, the statement said. Citing police documents, the Tampa Bay Times reported that he ordered them onto the ground and “informed all three victims that he was upset due to America bombing his Muslim countries.”

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After responding officers convinced him to let the hostages go, they took Arthurs into custody. That's when he told them that he killed two of his roommates and that their bodies were at their apartment, the statement says.

Jeremy Himmelman, 22, and Andrew Oneschuk, 18, were found there shot to death.

A fourth roommate, Brandon Russell, was found unharmed but later charged with illegally storing bomb-making equipment in his garage, according to court records.

Russell identified himself to police as a National Guard soldier, as well as a national socialist and a member of a group called the “Atom Waffen,” or Atomic Weapon, according to court records. On Russell’s dresser, court records say, he kept a framed photo of Oklahoma City bomber Timothy McVeigh.

Arthurs alleged that he and his roommates “shared a common neo-Nazi belief” until his recent conversion to Islam, according to court documents.

“He said his roommates disrespected his Muslim faith,” the statement said. “He also said he had become angered by what he described as the world's anti-Muslim sentiment and wanted to bring attention to his cause.”

Himmelman's sister, Lyssa, told the Times that her brother and Oneschuk had arrived in Florida a couple of weeks earlier from Massachusetts and immediately suspected that "something was off" with Arthurs. They planned to leave Sunday, she told the paper. She described her brother as a lover of animals and hiking, while Oneschuk was "a wonderful guy with a good heart."

Arthurs told authorities that Russell used neo-Nazi chatrooms, where he threatened to kill people and bomb infrastructure, the court records say.

After searching the apartment’s garage, bomb technicians found a cooler filled with explosive material, the records say. Nearby, they discovered electric matches and ammunition casings that could be used to detonate a bomb.

Russell told authorities that the explosives were for homemade rockets and balloons that he used for an engineering club at the University of South Florida, according to the court records.

A special agent with the Federal Bureau of Investigation, Timothy Swanson, said in the court records that the material was “too energetic and volatile” for such uses.