UPDATED 2:15 p.m. ET: Metro Nashville Police Department have apprehended murder suspect Travis Reinking. 

See below for original story.

The suspected gunman responsible for killing four people in a Tennessee Waffle House early Sunday morning called himself a “sovereign citizen," before being arrested outside of the White House in 2017.

The 29-year-old, Travis Reinking, who is still on the run following yesterday’s shooting, expressed views that reportedly align him with anti-government extremist groups, according to a police report that USA Today obtained.

During his clash with Secret Service in July 2017, Reinking told agents he needed to see Donald Trump to declare his sovereignty and inspect the grounds. He was arrested by the Metropolitan Police Department in D.C. after refusing to leave the area. Authorities confiscated his weapons after the incident, including the AR-15 used in the Waffle House shooting, but Reinking's father later returned them to him. 

The FBI defines sovereign citizens as those who “believe that even though they physically reside in this country, they are separate or 'sovereign' from the United States," according to USA Today.  They are also considered “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."

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It’s unclear just how extreme Reinking’s sovereign citizen declaration was, or if it had any influence in his decision to open fire on the Waffle House in Antioch, Tennessee. His past run-ins with law enforcement also include a June 2017 incident where Reinking threatened someone with an AR-15 and exposed himself to others at a public poolAccording to the Associated Press, he’s also threatened suicide and claimed the singer Taylor Swift was stalking him. In May 2016, Reinking told police officers in Tazewell County, Illinois, that Taylor Swift was hacking his phone.

A 2014 study from the National Consortium for the Study of Terrorism and Responses to Terrorism found that officers perceived these "sovereign citizens" as "the greatest threats to their communities.”