Increased attention toward the killing of black men and women by police throughout the past year has ignited national conversations on racism and law enforcement. From Freddie Gray in April 2015 to Deborah Danner — an “emotionally disturbed” woman fatally shot this week by an NYPD officer — protests around the country have forced many Americans to reassess how police engage with communities of color.

In light of — or perhaps despite — the increased scrutiny, FBI director James Comey told police officers at a national conference last Sunday that because of insufficient data on use of force, “Americans actually have no idea” whether racial bias in policing is really an epidemic. Pointing to current public outrage over police killings of African-Americans, Comey said “the absence of good information” and data has aided in the growing belief that police officers target particular communities.

READ MORE: Column: White people don’t understand the trauma of viral police-killing videos

“That is the narrative,” he told attendees of the International Association of Chiefs of Police. “It is a narrative driven by video images of real misconduct, possible misconduct and perceived misconduct.”

But even if there aren’t hard statistics, the problem of racial bias among police isn’t new. In fact, it’s been a concern of the FBI for at least a decade. Exactly 10 years ago this week, the FBI warned of the potential consequences — including bias — of white supremacist groups infiltrating local and state law enforcement, indicating it was a significant threat to national security.

In the 2006 bulletin, the FBI detailed the threat of white nationalists and skinheads infiltrating police in order to disrupt investigations against fellow members and recruit other supremacists. The bulletin was released during a period of scandal for many law enforcement agencies throughout the country, including a neo-Nazi gang formed by members of the Los Angeles County Sheriff’s Department who harassed black and Latino communities. Similar investigations revealed officers and entire agencies with hate group ties in Illinois, Ohio and Texas.

Much of the bulletin has been redacted, but in it, the FBI identified white supremacists in law enforcement as a concern, because of their access to both “restricted areas vulnerable to sabotage” and elected officials or people who could be seen as “potential targets for violence.” The memo also warned of “ghost skins,” hate group members who don’t overtly display their beliefs in order to “blend into society and covertly advance white supremacist causes.”

“At least one white supremacist group has reportedly encouraged ghost skins to seek positions in law enforcement for the capability of alerting skinhead crews of pending investigative action against them,” the report read.

Problems with white supremacists in law enforcement have surfaced since that report. In 2014, two Florida officers — including a deputy police chief — were fired after an FBI informant outed them as members of the Ku Klux Klan. It marked the second time within five years that the agency uncovered an officer’s membership in the KKK. Several agencies nationwide have also launched investigations into personnel who may not be formal hate group members, but face allegations of race-based misconduct.

“Many people in these communities of color feel they have been the subject of police violence for decades. And when an officer engages in conduct that adds or enhances that divide, they are ultimately jeopardizing the integrity of their agencies and putting their fellow officers in danger.”

Social media has made it easier to expose white supremacists who serve in law enforcement. In September 2015, a North Carolina police officer was fired after a picture of him giving a Nazi salute surfaced on Facebook. And as recently as August, the Philadelphia Police Department launched an internal investigation after attendees of a Black Lives Matter rally outside the Democratic National Convention spotted an officer in charge of crowd control with a tattoo of the Nazi Party emblem on his forearm and posted the image on Instagram.

“Many people in these communities of color feel they have been the subject of police violence for decades,” said Samuel Jones, professor of law at the John Marshall School of Law in Chicago. “And when an officer engages in conduct that adds or enhances that divide, they are ultimately jeopardizing the integrity of their agencies and putting their fellow officers in danger.”

Policing in America has historically had racial implications. The earliest forms of organized law enforcement in the U.S. can be traced to slave patrols that tracked down escaped slaves, and overseers assigned to guard settler communities from Native Americans. In the centuries since, many law enforcement agencies directly participated in antagonizing communities of color, or provided a shield for others who did. But in the 10 years since the FBI’s initial warning, little has changed, Jones said.

Neither the FBI nor state and local law enforcement agencies have established systems for vetting personnel for potential supremacist links, he said. That task is left primarily to everyday citizens and nonprofit organizations like the Southern Poverty Law Center, one of few that tracks the growing number of hate groups in America.

“We catch them when we can, which means when we notice someone and check in the database,” said Heidi Beirich, director of the Intelligence Project at the Southern Poverty Law Center. The group is responsible for exposing an Alabama officer as a member of a white nationalist hate group, League of the South, after he spoke at their national conference in 2013. The officer was later fired.

“Obviously, we do not want people with white supremacist or other extremist views to be in such positions, so it is important to screen them out,” she added.

The First Amendment’s freedoms of association and expression mean it’s perfectly legal for anyone to join a hate group — as long as it’s for the purpose of legal activity — and still be a member of law enforcement. They can even serve in other positions of public office. But according to the FBI memo, the government can limit employment opportunities of members “when their memberships would interfere with their duties.” Jones says that’s problematic.

“I cannot imagine that the FBI today could issue a report concerning any kind of threat without people being alarmed and wanting immediate action,” he said. “But in this case there seems to be almost an acceptance of it. The thought is ‘it’s just ideology and they have a right to believe this.'”

In response to our inquiry, the FBI said it “routinely shares information about potential threats to better enable law enforcement” but does not “comment on specific law enforcement bulletins.”

There are, of course, police officers who recognize racial bias and are calling for change. At the same conference where FBI director James Comey spoke of the uncertainty of policing bias, the head of the International Association of Chiefs of Police [IACP], Terrence Cunningham apologized for what he called “historical mistreatment” of racial minorities.

“While we obviously cannot change the past, it is clear that we must change the future,” he said. “For our part, the first step is for law enforcement and the IACP to acknowledge and apologize for the actions of the past and the role that our profession has played in society’s historical mistreatment of communities of color.”

These conversations come as the Department of Justice announced it’s launching a national database on use of force and deaths in police custody.

For many like Jones, it’s another step toward accountability. But questions remain on how to tackle bias early on: One way to do that, he said, would involve screening would-be personnel for bias and supremacist ties, something the FBI acknowledged as a threat a decade before viral videos of police killings became nearly a weekly discussion.

As the nation continues to examine the role of race in law enforcement, many like Jones question whether scrutiny of the infiltration by white supremacists will move beyond the FBI’s acknowledgement a decade ago to specific action in the decades to come.

“There needs to more direct enforcement,” Jones said. “It’s one thing to issue a memo, and another to have continued action after it. There was a warning 10 years ago and nothing else since then.”