The Justice Department will investigate the entire Ferguson Police Department

The US Department of Justice will investigate the entire Ferguson Police Department for civil rights violations, following the August 9 shooting of Michael Brown by Ferguson police officer Darren Wilson, the agency announced on Thursday.

The investigation, which will run at the same time as ongoing local and federal investigations into Wilson and the shooting of Brown, will look at whether the police departments have systematically violated the civil rights of local minority communities. The Justice Department, through the the Community Oriented Policing Services (COPS) Office, will also help the St. Louis County Police Department change its policing practices, including policies and training regarding use of force.

“The Department of Justice is working across the nation to ensure that the criminal justice system is fair, constitutional and free of bias,” Attorney General Eric Holder said in a statement. “Ferguson and St. Louis County are not the first places that we have become engaged to ensure fair and equitable policing and they will not be the last. The Department of Justice will continue to work tirelessly to ensure that the Constitution has meaning for all communities.”

Ferguson is predominantly black, but its local government — including its police force — is almost entirely white. The racial disparities have fostered tensions in the small St. Louis suburb, which culminated in the August protests that followed Brown’s death. Other towns in the area suffer from similar racial disparities.

The Brown shooting, in other words, is part of a much bigger issue with local police. At least five Ferguson police officers, besides Wilson, have been named in lawsuits claiming civil rights violations, according to the Washington Post. Although the town of Ferguson is roughly 67 percent black, a report from the Missouri attorney general’s office found black residents made up more than 93 percent of arrests carried out by Ferguson police that same year.

Under Holder, the Justice Department has initiated more than twice as many civil rights investigations on police departments than his predecessors did in a similar time period. At least 34 police departments are currently under review, according to the Washington Post.

The idea behind these reviews is to identify any systemic issues. As the Atlantic’s Ta-Nehisi Coates pointed out, the investigations have the potential to uncover systemic failures instead of just singling out one police officer for what could be part of a much bigger problem.

The US criminal justice system in many ways disproportionately hurts black Americans. Although black and white people use and sell drugs at similar rates, black people are much more likely to be arrested for drug possession. And when they’re convicted for drug charges, black Americans face considerably longer sentences — in part because sentencing laws treat crack cocaine, one of the few drugs more popular among black than white people, much more harshly.

The disparities explain why Holder’s Justice Department — and law enforcement experts — are taking the issue of racism in the criminal justice system much more seriously. After decades of complaints, events like Ferguson have helped bring the issues to the mainstream.

To learn more about racial disparities in the criminal justice system and Ferguson, read the full explainer and watch the video below:

Update: This post was updated to reflect the official announcement and new details.