The evidence for racial disparities in the criminal justice system is well documented. The disproportionate racial impact of certain laws and policies, as well as biased decision making by justice system actors, leads to higher rates of arrest and incarceration in low-income communities of color. However, there is no evidence that these widely disproportionate rates of criminal justice contact and incarceration are making us safer. This brief presents an overview of the ways in which America's history of racism and oppression continues to manifest in the criminal justice system, and a summary of research demonstrating how the system perpetuates the disparate treatment of black people. The evidence presented here helps account for the hugely disproportionate impact of mass incarceration on millions of black people, their families, and their communities.