A man charged with killing two roommates told Tampa police he did so because they disrespected his recent conversion to Islam.

Meanwhile, a third roommate is accused of having explosive materials.

Devon Arthurs, 18, faces two murder charges in the Friday slayings of Jeremy Himmelman, 22, and and Andrew Oneschuk, 18.

They lived in the 15000 block of Amberly Drive, where the fatal shootings took place, according to investigators.

The shootings happened just before 5:30 p.m. Arthurs was taken into custody while at Green Planet Smoke Shop on Amberly Drive. Police said he held two customers and an employee hostage before letting them leave.

In a news release issued Monday, the Tampa Police Department said, "When detectives interviewed Arthurs and inquired about a motive for the killings, Arthurs claimed that he and his roommates shared a common neo-Nazi belief, until Arthurs recently converted to Islam.

"He said his roommates disrespected his Muslim faith. 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."

Details from the interview with Arthurs have been shared with the FBI, police said.

The investigation is still under way.

Third roommate charged by FBI

Over the weekend, the Federal Bureau of Investigation arrested Brandon Russell, 21.

According to a criminal complaint, agents found Neo-Nazi propaganda in Russell's bedroom, along with a framed picture of Oklahoma City bomber Timothy McVeigh.

Agents said they also found explosives and a destructive device that Russell admitted.

Russell told agents he was in the University of South Florida engineering club and that the explosives were to boost homemade rockets and send balloons into the atmosphere.

The FBI says that material is too energetic and volatile for those types of uses.

Russell was charged with possession an unregistered destructive device and unlawful storage of explosive material.