UPDATE (May 23) | New court documents filed Tuesday regarding Devon Arthurs' charges state that he killed his two roommates, in part, to prevent them from committing acts of planned domestic terrorism.
The FBI has refused to comment about the investigation, only that they don't believe there is an imminent threat to the community.
The group they're accused of being a part of is called the Atomwaffen Division. Propaganda spread by the group notifies people to visit their message board on Ironmarch.org. Some members of the message board describe Brandon Russell as the leader of the Atomwaffen group.
Meanwhile, the Florida Army National Guard released more information about Russell. He joined the ANG in February of 2016. He is currently a Private First Class in an infantry unit located in Pinellas Park.
A spokesperson for the Florida National Guard says they are not aware of him trying to recruit other soldiers into his neo-Nazi group, but the investigation is in its early stages. It's not clear if he will eventually face charges under the Uniform Code of Military Justice.
ORIGINAL STORY (May 22) | An admitted neo-Nazi now faces federal charges after agents discovered bomb-making material in his Tampa Palms apartment during a double homicide investigation.
But local Islamic leaders tell ABC Action News, it's unlikely Arthurs properly converted to their religion.
Aida Mackic, civil rights coordinator for Council on American-Islamic Relations, says the group has no record of Arthur's proclaimed conversion.
"None of the Islamic centers here are aware of this individual," said Mackic. "Men, in particular, it's mandatory for them to attend Friday prayers in congregation and this individual, like I said, we weren't aware of his attendance in any of the local mosques here."
According to a federal criminal complaint, the F.B.I. is now investigating a fourth roommate, confessed neo-Nazi Brandon Russell.
Federal documents state, 21-year-old Russell came home from Army National Guard duty Friday night to find the bodies of his two roommates, Jeremy Himmelman and Andrew Oneschuk.
Agents uncovered scores of explosive materials stored in Russell's garage during the homicide investigation Friday night.
It included a "white, cake-like" substance in a cooler that tested positive for hexamethane triperoxide diamine, also known as HMTD, a precursor for several types of explosives.
They also found empty 5.56-caliber bullet casings with fuses agents warn could be used as detonators.
Federal agents also discovered guns, ammo and a framed picture of Oklahoma City bomber Timothy McVeigh inside Russell's bedroom.
Monroe County deputies arrested Russell Sunday in Key Largo.
Russell told investigators that he's a national socialist and a member of "Atomwaffen," which is atomic weapon in German.
The radical, militant groups is known for spreading Nazi ideology on college campuses.
ABC Action News has confirmed, Russell was a student at the University of South Florida in the spring 2017 semester but had not signed up for fall classes.