Authorities say investigators found white supremacist propaganda, bomb-making materials and a framed photograph of Oklahoma City bomber Timothy McVeigh at a Florida apartment where a teenager killed two roommates who once shared his neo-Nazi beliefs before he converted to Islam.

According to police and FBI reports released Monday 18-year-old Devon Arthurs led police to the two bodies inside his Tampa apartment last Friday, saying he killed them after they disrespected his new faith.

A fourth roommate, a member of the Florida National Guard, was arrested on charges related to the alleged discovery of bomb-making materials.

A Tampa police report says Arthurs said he converted to Islam and was upset about American bombings in Muslim countries, among other issues. He is being charged with two counts of first-degree murder.