Baton Rouge Shooter Linked to Black Sovereign Movement

A year before he gunned down three police officers in Baton Rouge, Louisiana, Gavin Long filed to legally change his name to Cosmo Setepenra and declared himself a member of an indigenous "nation" governed by "special laws," according to court documents.

The group, called the United Washitaw de Dugdahmoundyah Mu'ur Nation, Mid-West Washita Tribes, is described in the filings as having members who "embody historical continuity with societies, which existed prior to the conquest and settlement of their territories by Europeans... (as well as peoples brought involuntarily to the New World who freed themselves and re-established cultures from which they have been torn)..." according to the May 2015 filing.

The members also include "tribal people" who have unique "social, cultural and economic conditions" and whose "status is regulated wholly or partially by their own customs or traditions or by special laws or regulations," say the documents, which were reported by The Kansas City Star.

In the wake of Sunday's shooting, a source briefed on law enforcement's investigation told ABC News it appeared Long also had shown support online for the Moorish Science Temple of America, which was described in an unrelated lawsuit as a group that does not believe the descendants of slaves are subject to U.S. laws. A spokesperson for the group said Long was not a member and that the group's teachings do not espouse "criminal activities."

Oren Segal, Director of the Anti-Defamation League's Center on Extremism, told ABC News both groups fall under a broader "Moorish movement" that shares some ideology with the more prominent and usually extreme right-wing sovereign citizen movement.

"While still retaining most 'traditional' sovereign citizen pseudohistorical and pseudo-legal theories, Moorish sovereigns added new ideas, including the notion that African-Americans had special rights because of a 1780s treaty with Morocco, as well as the belief that African-Americans were descended from African 'Moors' - and often also the belief that African-Americans were also a people indigenous to the Americas," he said.

The Washitaw Nation began in the mid-1990s in Louisiana and claims its members are descendants from the "ancient mound-builders of the Mississippi-Missouri Valley," Segal said.

Last September, a self-declared "free Moorish national," named Olajuwon Ali Davis, was sentenced to seven years in prison after pleading guilty to charges related to a purported plot to blow up the Gateway Arch in St. Louis, Missouri. In a video uploaded to YouTube in 2013, Davis says that he had changed his name and declared his new "nationality," meaning he was no longer subject to many U.S. laws, carried his own self-made identification card and no longer had to pay taxes.

"I am no longer a slave to the Matrix," Davis says in the video, which was previously reported by The St. Louis Post-Dispatch.

Long, who was active online under the name Cosmo until just hours before he was killed in his attack, uploaded some videos of sovereign citizens' interactions with authorities but does not appear to have discussed links to the Moorish movement.

Long's May 2015 name change filing lists a mailing address in the Washitaw Terra, along with what appear to be GPS coordinates, otherwise known as a P.O. Box in Long's hometown of Kansas City, Missouri.