Then why not better train, screen, and pay the parole officers? These people seem to be a key part of the system which would be overseeing people who have a high chance to commit a crime. The parole officers should definitely try to fairly assess the parolee's life circumstances and try to best assist them in finding a job and crime-free life in normal society.

I've heard stories of parole officers being hard on parolees but the parolees were also thankful because it forced them to turn their lives around.

40% seems very high but the people who sentence and lock-up parolees who violate their parole are likely much better equipped and trained to judge the parolees.

Just my 2 cents.