I wonder if Dr. Sowell is familiar with the life of Reuben Greenberg (retired police chief of Charleston SC)? His view of the role of police and the justice system was unbelievably effective. He looked at the costs of crime by adding in the cost of investigation, trial and incarceration. He pointed out that there is a small cadre of repeat offenders who will continue their criminal patterns whenever they are at large. The cost to track them down, build a case, and then go to trial where generally the state had to pay for the prosecution, the defense (public defender), the court room staff, the judge, and the the entire court system infrastructure is enormous.
He used to take victims and family of victims to EVERY parole hearing because it was cheaper to pay their way than to let the perps out to start over again.