Results of the U.S. Justice Department’s investigation of law enforcement practices in Ferguson, Mo., were revealing but likely not very surprising for thousands of Americans of color — too many of whom regularly face race-based bias.

Federal investigators found that while blacks make up two-thirds of the Missouri city’s 21,000 residents, over the past two years they accounted for 85 percent of the traffic stops, 90 percent of the tickets and 93 percent of all arrests. The data led to only one explanation: The Ferguson Police Department has routinely violated the constitutional rights of black residents.

The federal report does not justify or excuse the violence that occurred in Ferguson after black teenager Michael Brown was shot and killed by a white cop — nor should it. But the thorough study does vindicate hundreds of Ferguson citizens who peacefully protested over police practices in their city. It also validates the efforts of thousands across the country who have peacefully demonstrated while carrying “Black Lives Matter’’ posters.

And it confirms what too many people of color know through lifetimes of experience — racist, discriminatory attitudes and actions are alive and well in many corners of this country.

Those attitudes are especially damaging — and dangerous — when held by law enforcers who carry guns and have the authority to arrest, jail and kill. In Ferguson, bias so permeated the Police Department that cops felt free to share racist, disparaging jokes and other comments about black people in office e-mails.

And, sadly, Ferguson is not alone. During the past several years the Justice Department has conducted more than 20 investigations and issued similar findings against cities including Cleveland and Newark, N.J. Those reports have led to settlements with directives for actions such as officer training and community dialogues — forced under threat of lawsuits for constitutional violations. In Minneapolis, the Police Department is currently working to respond to concerns raised by a Justice Department evaluation of community relations.

Decades of research keep reaching the same conclusion: Despite notable progress in race relations, bias remains deeply ingrained not only in American culture but also within public, taxpayer-supported institutions. Think about the children and young men who are growing up in Ferguson and cities like it across the country. Their fears of being harmed rather than helped by some officers are real.

Beyond studies, settlements and training, more must be done to truly relegate racism to the history books. Americans of goodwill must demand better and accept nothing less than fair treatment, especially from public agencies whose employees are entrusted to keep the public safe.