The funny thing is that research conducted by very liberal criminologists--the best in the world--shows that, while there are episodes of racism, there are also episodes of paternalism, but there is no systemic or intentional bias.
From Heather MacDonald's piece in the City Journal:
In 1997, criminologists Robert Sampson and Janet Lauritsen reviewed the massive literature on charging and sentencing. They concluded that “large racial differences in criminal offending,” not racism, explained why more blacks were in prison proportionately than whites and for longer terms. A 1987 analysis of Georgia felony convictions, for example, found that blacks frequently received disproportionately lenient punishment. A 1990 study of 11,000 California cases found that slight racial disparities in sentence length resulted from blacks’ prior records and other legally relevant variables. A 1994 Justice Department survey of felony cases from the country’s 75 largest urban areas discovered that blacks actually had a lower chance of prosecution following a felony than whites did and that they were less likely to be found guilty at trial. Following conviction, blacks were more likely to receive prison sentences, however—an outcome that reflected the gravity of their offenses as well as their criminal records.
Another criminologist—easily as liberal as Sampson—reached the same conclusion in 1995: “Racial differences in patterns of offending, not racial bias by police and other officials, are the principal reason that such greater proportions of blacks than whites are arrested, prosecuted, convicted and imprisoned,” Michael Tonry wrote in Malign Neglect. (Tonry did go on to impute malign racial motives to drug enforcement, however.) The media’s favorite criminologist, Alfred Blumstein, found in 1993 that blacks were significantly underrepresented in prison for homicide compared with their presence in arrest.
Sampson, Tonry, and Blumstein are surpassed by perhaps only James Q. Wilson in their status among criminologists. The more ignorant the commenter, the more one is likely to say the system is rigged. Community college instructors who never read anything but their assigned textbooks just KNOW the system is designed to ruin the lives of blacks.
Sure there are bad apples, but there are way too many safeguards for them to have their way. Plus, like the famous Crip Kody Scott said, cops just want to catch the bad guys. But liberals LOVE to believe that under the badge of every cop lies a hateful heart.