Good thing that the number of bad cop arrests is not 0 then. I don't get why people have issues with sending law enforcement to the places where there is literally more crime.
Imagine a road network and police with a limited number of speed traps. If you send the speed to the places where there have been more people caught speeding then the fact that the speed traps where in that location will have a higher rate of caught speeders.
Another example is drug enforcement. Black people are searched more often then white people for drugs, which results in them being caught having drugs more often which in turn makes police think that they are more likely to have drugs.