With prisons you have two options
- worry about re offending, and reducing crime rates/ keeping society safer
2)worry about punishing/ making sure that crime is severely punished and a strong message is put out, and a strong deterrent.
Generally it's proven that strong punishments eg life long imprisonment and death penalties don't improve offending rates
The system we have is based on criminals re entering society at some point and we have to equip them
Having worked within the system myself I've seen prison stays that have completely increased the risk to society. For example someone one goes in, loses their job, loses their accommodation, loses touch with relatives, is linked out of the benefits system, develops an addiction, loses touch with general society and is totally overwhelmed by life. They immediately leave have no accommodation, no support, potentially no money and re offend because either they want back in or because they feel they have no choice.
In reoffending you hope that it's breaking into a garden shed or something but often it's crimes with a real impact on a victim
You also have to weigh up the ability of being able to manage people in prison. The latest stats for example show there were more incidences of self harm in prisons then there were prisoners, that the suicide rate is high, and the assault rate on staff is high
People with nothing to lose are aggressive, and difficult to manage.