Laws are different from state to state. In GA, neither the teachers nor parents were made aware of those w/ police records. Occasionally, even administration was not informed if it was deemed too "prejudicial." For example, I learned after the fact that one of my students was a convicted sex offender. I learned this after he was sent back to juvy for raping another of his sisters on Xmas break. Of course, before Xmas break he was caught climbing into the ceiling of the boys bathroom to peer into the girls bathroom stalls (which I used along w/ many of the students). His punishment for that infraction? 1 day ISS. I did not learn of the "peeping" until he was gone. The admin. did not know to report the incident to his parole officer because we were not permitted to know he was a sex offender!
I taught in MN, and the same was true. No teachers were informed of a student's past. Like your example, I later found out I had taught students who were convicted of just about every offense except murder, but I was never privy to the info until they finally were suspended for good.