There are quite a few people who murder despite the risk of incarceration. I would love a system that approaches it more like: "you've lost trust of this civilization to act in good faith, and now you will be contained in a way that can rebuild that trust, and you will not be allowed to re-enter this civilization until you have indeed rebuilt that trust."

We'll probably never get there.

The only time it's worked is in El Salvador and it was because they arrested the 2% of the population who had the potential to be murderers and have so far thrown away they key. I imagine before too long they will also have a final solution to the problem of feeding them for the next 50 years.