You have some real concerns about your co-worker's treatment of offenders. You hear him screaming obscenities at them in his office, and one time you saw him pat a female probationer on the rear end and say, "Be sweet to me and I'll keep you out of jail." On the other hand, no one else seems to notice anything is wrong.
Is there anything wrong?
Did you misinterpret the exchange; should you do anything about this, if so, what?