The alleged Waffle House shooter had declared himself to be part of the rightwing extremist "sovereign citizen" movement, according to USA Today.
Travis Reinking, 29, is believed to have been the shooter who killed four at a 24-hour diner outside Nashville. Reinking had been arrested outside the White House last year and had his guns taken away because he is mentally ill, according to reports.
At the White House, Reinking had declared himself a "sovereign citizen" who is not required to follow the nation's laws.
The FBI says that sovereign citizens are "anti-government extremists who claim the federal government is operating outside its jurisdiction and they are therefore not bound by government authority—including the courts, taxing entities, motor vehicle departments, and even law enforcement."
Reinking's massacre was stopped when hero James Shaw Jr. took a bullet to get the gun off him and throw it away. Shaw has said he's not a hero—that he was just trying to save his own life and ended up saving others in the process.
Reinking is still at large in Tennessee after sunset and police believe he may be armed.