Even if they are completely racist in their arrests, so what? The strategy of the system is to identify serious repeat offenders and take them off of the streets.
If there is a corresponding decrease in crime, it is mostly safe to say that the strategy is effective. If five years from now there is a negligible decrease or an increase in crime, we can start having a serious discussion about the merits of the system.
The article gives a couple of good examples of how the system has been used. Here is one example, there are others that you can review for yourself...
"In May we created our crime-strategies unit. Wilmington has one of the highest violent-crime rates in the country, but 1 to 2 percent of the people are doing 70 percent of the crimes. We’ve taken dozens of high-risk offenders off the street.”
Presumably, within a few months to a year, they will be able to check crime stats and determine of the absence of those high-risk offenders has had a measurable impact on crime.
I think what you will see is that it does. The reality is that the truly anti-social, dangerously violent, willing to use force on other human beings types of criminals are a small percentage of the overall criminal population. If you focus on removing those severe cases, it will take a while for the population to produce more of them.
To a lesser extent, the same thing happens with property crimes. Let's say you have a guy who likes to smash car windows and steal things. He has a few friends who see him getting away with it and they adopt the same behavior. They tend to work a particular neighborhood. If you take those guys out of the equation, that neighborhood will see a decrease in that kind of crime for a little while. But if you let it go unchecked, it will increase. Other criminals will start to realize, "Hey, let's go down to VehicleTheftVille and get some center console change" because the police do not seem to be doing anything about it, and everyone else is doing it.