I don't know that I have much to add to the good, better, best discussion, but I wanted to share a few stories (don't know what good they will do):
1. We had a cub scout leader years ago who refused to provide her SSN for the BSA background check. The bishop said that she was a member in good standing and held a TR, so he wasn't concerned about the BSA approval. It was odd.
2.An older gentleman in our ward was accused years and years ago of inappropriate actions against a young woman. The authorities were never called (despite the fact that the YW's father was a police officer) and the family moved out of the ward. That YW is now a grown woman and is attending a different church with her children. When my husband became bishop, he checked this accused man's membership record and sure enough, there IS a red flag by the man's name. It's there when ministering assignments are made and my husband has to manually approve those assignments. This man is not to be assigned to a family with children (nor will he ever hold a primary or YM or youth SS calling). While there isn't a background check, there are red flags when something has been brought to the ward leadership's attention. This man was never brought in for church discipline. It was left at "accusation-level" only, but there is still a red flag placed there. It's better than nothing.
3. Another family in another of our wards had an issue with a young adult male primary teacher. He crossed the line with their young daughter. The family fought for punishment on the ward level, but didn't pursue it on a legal scale. It was kept very quiet and even now (decades later), neither party talks about it. However, shortly after this family moved, the young man found a teenage girl to date...and we saw a similar story with her. Her family moved as well and there was a major ward division (who did we believe? The young man or the girl?). Had ANYONE talked openly about his actions with the primary girl, this teenage girl may not have fallen victim to the same young man.
4. My husband is also a mandatory reporter for his job (and as a bishop) and I know for a fact that we have a mom of several young children who routinely looses her cool with them and is borderline emotionally abusive to a few of them (I've seen it). She is a good friend of mine, so I don't tell my husband b/c then he has to make the call, right? If he makes the call, we lose her and the family to bitterness and inactivity. The fallout from a CPS call would be devastating. Am I protecting her or am I protecting him?
5. Two-deep leadership is becoming almost essential in ANY situation with the youth. I am a seminary teacher. I was waiting in the hall by the door to the church one morning, watching for one particular student to arrive (we have 3 other teachers in the building who teach close to the outside door). I greeted kids as they came in, but I was alone in the hall with them as I did so. Apparently, I offended one of the youth with my greeting and as this youth passed the story around class, it morphed into something far worse and parents of other youth were getting concerned. I finally received a phone call from one mom blasting me for my actions. It was ugly, but because I had no other adult with me, my defense was useless.
We really are raising kids in a cultural society where they are trained to look for offense. I'm sure we've all been in situations like that. It's only getting worse.
6. If background checks were mandatory,
-how often would they be run?
-how many people would refuse to do them (for whatever reason) and, therefore, decrease the number of badly needed primary teachers?
-what would happen if someone agreed to the check, it came back dirty and the person was either released or never given a calling?
Ward members would be curious and would we be creating a state of suspicion and gossip?