Five years ago, a white police officer in Ferguson , Missouri, shot a young Black man, Michael Brown , and decades of frustration over racially biased and unconstitutional policing exploded in the streets as the world watched.

In the months and years that followed, the Obama administration helped draw national attention to the utility of federal investigations into patterns of unconstitutional conduct by police departments. But now the Trump administration has all but abandoned that work. The Justice Department has backed away from its mandate to rein in systemic police abuse and deserted even those police departments that asked the feds for help.

The Justice Departments Civil Rights Division, which is charged with investigating and litigating any unconstitutional pattern or practice of conduct by law enforcement officers, virtually halted new investigations. Political appointees of President Donald Trump tried to sabotage one reform agreement in Baltimore and block another in Chicago.

It has taken a toll inside the Justice Department. HuffPosts interviews and research indicate that roughly a third of the thinly staffed group that investigates police practices at the Civil Rights Divisions Special Litigation Section have departed since Trumps election. The Trump administration has shrunk the size of the unit and has no plans to replace those who left.

Supporters of DOJ-led police reform see an irony in an administration that came into office on a law and order platform abandoning its duty to enforce the law against police. The administrations retreat from systemic police reform is yet another example of it shirking its duty to the rule of law, says former Civil Rights Division official Chiraag Bains.

Im not sure there are many more bodies of work that are so clearly about rule of law at their core, Bains said. Talk about law and order: What higher law is there than the Constitution of the United States? Thats what these cases are about.

A Justice Department official said in a statement that the agency is committed to protecting the civil and constitutional rights of all individuals, and understands the important role the Department plays in helping communities and police departments as they seek to achieve the same goal while fighting violent crime and protecting public safety. Attorney General William Barr, the statement said, is committed to holding any officer responsible who violates the law without restraining the ability of good police officers trying to do their part in reducing violent crimes.

Under a provision of federal law codified in 1994 in the wake of rioting in Los Angeles, which was sparked by the acquittal of officers filmed beating motorist Rodney King, the Justice Department can investigate and sue over widespread police misconduct. The investigations can highlight racism within a departments culture, flag broken internal affairs systems that fail to hold officers accountable for misconduct and identify practices that systematically squash constitutional rights. The Ferguson report, released seven months after Browns death, did all three. One distinguishing feature of the Ferguson report was its focus on the conspiracy between the citys part-time municipal prosecutors, judges, police force and bureaucracy to implement a policing-for-profit scheme to implement a regressive tax on Ferguson residents and visitors.