The big red building is part of ATT- it disrupted communications and air traffic in Nashville, too.
One report said that he filed a quit claim deed to transfer ownership of the house to a woman from California. The voice in the recorded warning sounded female- another report said that he had experience in security systems and electronics.
This link indicates that the shell casings may be from rounds that went off because of the blast-
FBI Special Agent in Charge Doug Korneski said Saturday there is no indication of additional explosive threats.
www.cbsnews.com
The house and yard look decent- might have expected someone from the hills, living the way the Unibomber had.
Maybe he was tired of ATT's crappy Customer and Technical Support.