Baton Rouge shooting suspect Gavin Long had ties to an anti-government movement called Sovereign Citizens.
Followers believe government has no legal authority over them.
Ironically, Sovereign Citizens started as an branch of the white separatist movement about 40 years ago.
Jackson County documents show Long was a follower of an all black part of that group called the Moorish sect. Sovereign Citizens expert J.J. MacNab estimates there are roughly 40,000 to 50,000 followers of the Moorish sect. She says they're mainly in urban areas like Kansas City and followers would say they don't belong to anything.
Investigators are now exploring Long's connection to the movement.
"Their beliefs may sound so out there that they appear comical or crazy, but don't discount or ignore these people because they are willing to kill or be killed for these beliefs," said Bob Paudert.
Paudert, who's the West Memphis, Arkansas, police chief, made those comments in a Florida Sheriff's Association training video.
The video was made to alert law enforcement officers to the dangers of encounters with Sovereign Citizens.
In the video, Paudert recalls a day in 2010 when a Sovereign Citizen gunned down two men from his department after making what they thought was a routine traffic stop.
The chief's son was one of the officers killed.
"We as law enforcement officers need to recognize this very real threat so we can protect ourselves," Paudert says in the video.
The FBI classifies some Sovereign Citizen extremists as domestic terrorists.
According to a 2014 national law enforcement survey, responders concluded the movement was the single greatest threat to their communities, ranking above Islamic terrorists and jihadists.
Federal records show Sovereign Citizen violence has taken place across the country.
Long left a social media and paper trail showing what he believed. In a tweet from July 10, he wrote, "Yes the Govt is a hate Group. They Hate Black People."
Jackson County documents Long signed last September revoke his power of attorney. It states for "any and all such contracts issued by any and all government or quasi-government entities due to the use of various elements of fraud by said agencies to attempt to deprive me of my sovereignty and/or property."
In the same documents, Long changes his name to Cosmo Ausar Setepenra, which includes a new Moorish birth certificate with that name.
In addition to the Moorish sect of Sovereign Citizens, MacNab says the larger Patriot sect has another estimated 400,000 Americans.
Kansas City Police Department spokesman Darin Snapp says the agency does have training on the Sovereign Citizens movement every couple of years.