EPA USA CRIME SHOOTING NASHVILLE CLJ CRIME USA
A handout photo made available by the Metro Nashville Police Department reportedly shows Travis Reinking who is sought after by police in connection with a shooting at a Waffle House restaurant outside Nashville, Tenn. on April 22, 2018. According to police, four people were shot dead and others wounded after a nude gunman opened fire on the guests at the restaurant in the early morning. Police have started a manhunt and identified Travis Reinking as person of interest in the shooting.
METRO NASHVILLE PD HANDOUT, EPA-EFE

The suspected gunman on the run after riddling a Tennessee Waffle House with bullets dubbed himself a "sovereign citizen," before being arrested in July 2017 outside the White House.  

Travis Reinking, 29, used that term — which the FBI has also used to describe a group of anti-government extremists — during a clash last year with the Secret Service, according to a police report obtained by USA TODAY. 

Reinking told agents he needed to see President Trump and defined himself as sovereign citizen who had a right to inspect the grounds, according to an arrest report by the Metropolitan Police Department in D.C. He was arrested on an unlawful entry charge after refusing to leave the area. 

The FBI has said sovereign citizens "believe that even though they physically reside in this country, they are separate or 'sovereign' from the United States." 

The agency has also defined sovereign citizens as "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."

It's unknown if Reinking's 2017 sovereign citizen self-designation was in line with the FBI's definition or if it played any role in the Antioch, TN Waffle House attack, which left four dead. 

A motive has not been released and investigators are continuing to probe Reinking's background, which includes several past incidents with law enforcement. 

In June 2017, Reinking threatened someone with an AR-15 then drove to a public pool and exposed himself to others, said the USA TODAY Network's Tennessean, citing police records. He has also threatened to kill himself and said he thought singer Taylor Swift was stalking him, according to the Associated Press

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Many sovereign citizens are harmless or commit petty or "quirky" crimes but some have been known to become violent, the FBI says

The bureau says usually, these individuals believe the law doesn't apply to them and don't have to pay taxes or follow other norms. They believe governments are illegal and gravitate to conspiracy theories. 

"If someone challenges their ideology, the behavior of these sovereign-citizen extremists quickly can escalate to violence," the FBI said in 2010, noting the movement is likely to continue to grow because it is "fueled by the Internet."  

There weren't any reports of violence in the 2017 White House incident. Authorities say Reinking took off his tie, balled it into a fist, continued walking toward the White House and told agents they could arrest him if needed. 

"Do what you need to do. Arrest me if you have too," he said, according to the report. 

The sovereign citizen movement has continued over the years. The Southern Poverty Law Center, a nonprofit legal advocacy organization that tracks hate groups, has continued to monitor such individuals and their crimes and has written about nearly 10 incidents this year. 

The SPLC notes these individuals usually take part in protests against governments or use "paper terrorism," which is filing bogus lawsuits and fake liens on properties, to carry out their mission of disorder.

But sometimes, these individuals have gotten violent. 

The gunman police say killed three law enforcement officers in Baton Rouge, LA in 2016 amid heightened tensions between members of the black community and law enforcement also identified as a sovereign citizen.

A 2014 study of law enforcement across the country by the National Consortium For the Study of Terrorism and Responses to Terrorism found officers perceived these individuals as "the greatest threats to their communities," topping Islamic extremists. 

Follow Christal Hayes on Twitter: Journo_Christal