When police arrived at the Hamptons apartment complex in New Tampa Friday evening, they searched for explosives...and found some.
According to a federal criminal complaint, investigators found the explosives in a cooler owned by one of Devon Arthurs' roommates, Brandon Russell.
Russell happened upon the crime scene after returning from National Guard duties and investigators say he admitted owning the explosives as part of a engineering club at USF.
But the FBI wasn't convinced. Russell was arrested during a traffic stop in Key Largo on Sunday, facing federal charges.
Friday, police responded to a New Tampa smoke shop where they say Arthurs had taken three hostages. He surrendered and led police to the apartment complex, where police found the bodies of Jeremy Himmelman and Andrew Oneschuk.
Police say Arthurs mentioned that he was a neo-nazi-turned-muslim and that his roommates were also neo-nazis. Police say he admitted he shot and killed Himmelman and Oneschuk because they disrespected his faith and wanted to bring attention to his cause.