A classified FBI report recently obtained by The Intercept reveals that the intelligence agency has been keeping track of white supremacists who maintain an active presence in US law enforcement agencies.

The FBI Counterterrorism Policy Guide from 2015 reports that “domestic terrorism investigations focused on militia extremists, white supremacist extremists, and sovereign citizen extremists often have identified active links to law enforcement officers.” Yet despite this threat, the FBI has largely been keeping this information under wraps.

In 2009, a Department of Homeland Security intelligence study concluded that “lone wolves and small terrorist cells embracing violent right-wing extremist ideology are the most dangerous domestic terrorism threat in the United States.”

The report also suggested that “disgruntled military veterans” might be ripe for recruitment, which drew immediate outrage from conservative lawmakers and Tea Party candidates. The backlash resulted in the report's lead investigator being pushed out.

“They stopped doing intel on that, and that was that,” said Heidi Beirich of the Southern Poverty Law Center. “The FBI in theory investigates right-wing terrorism and right-wing extremism, but they have limited resources. The loss of that unit was a loss for a lot of people who did this kind of work.” Daryl Johnson, lead researcher on the DHS report, noted that the FBI is the only agency still investigating domestic extremists. “There’s not even any training now to make state and local police aware of these groups and how they could infiltrate their ranks,” he said.

After internal investigations rooted out large numbers of right-wing extremists in the US military, the Department of Defense imposed stricter screenings to keep these extremists out of military positions.

“The military has completely reformed its process on this front,” Beirich said. “I don’t know why it wouldn’t be the same for police officers; we can’t have people with guns having crazy ideas or ideas that threaten certain populations.”