I'm with Custardo, people can become better, and we need to spend more on rehabilitation.
But the core of the problem is how do we tell if they really are better people now ?
This sort of thing is far from a precise science.
I don't know how you "fix" sex offenders, thus you need to keep them locked up. Some are on record as pleading with the authorities to be taken in because they cannot control themselves.
Although many are to some degree mentally ill, they are capable of feeling fear. This requires that they are caught, and that their punishment is sufficiently scary that our government is condemned by human rights organisations. I favour whipping, followed by imprisonment.
Although not a fan of Islam, they have the right idea on this stuff. Hard to rape someone if you don't have hands, or eyes.
I'm against the death penalty. It's simply not cruel enough. Castration has been tried, and it doesn't actually work that well. The details of how it fails are quite gruesome...
In relase of criminals there is a degree of risk managment, but the system is defective. I think of a prison as a bit like a factory, and we sadly note that many people have their criminality upgraded whilst inside.
But everything that comes out of any factory has some chance of going wrong in a very bad way, in the same sense that prisoners reoffend.
But if my company sold fridges where 1% of them had defects that put poeple in hospital. I'd be sued out of business very quickly. If if were shown that I knew of the risks, it would cost me even more.
The government currently sees letting rapists, murdererers, and general thugs out as a cost saving measure. The "cost" of someone getting raped is zero in that form of accountancy. There is "criminal compensation", but it's small, and doesn't take into account government culpability.
If my firm had caused a baby to get raped, knowing that we could have stopped it, would cost an enormous pile of money, and probably my job. I'd try damn hard to stop that.
Has anyone on a parole board, ever once been disciplined in any way whatsoever for letting out a criminal who murdered, raped etc ?
That cost would balance the cost of keeping people in jail long enough for them not to be a threat any more, and yes that means decades.
However, if government were liable for the acts of people it released into the community, there would be an incentive to fix them better, and let out fewer of the worst offenders.
Tagging could be made to work, some of the (admiddedlu rather overkill) security gear in my home PC network is beyond most organised crime to hack. Tags that fall off and aren't monitored, dont work.
As I said earlier, literacy correlates well with criminality, fixing that is not cheap, a few K£, and it doesn't have a "benefit" that the government measures.