In a small handful of cases, such as murder cases, the reason for using jail time as a punishment is to keep someone out of open society. In the vast majority of cases, though, prison is used to curtail crime and act as a reforming device.
You don’t put someone in jail for shoplifting because they’re a massive danger to society. You do it because you want them to stop shoplifting, and you think the jail time will work toward that goal.
But it doesn’t. Contrary to what a lot of people who have never to prison believe, those who spend time in jail often commit more crimes when they get out. It makes things worse. Prison doesn’t reform anyone.
Part of the problem is that those who get arrested often have tough living situations from the start. Someone who is surrounded by violence and drug use isn’t going to get out of jail, swear off that lifestyle, buy a house in the suburbs, get a job in a local office building and spend their weekends mowing the lawn. They’re just going to go right back into that same atmosphere of drug use and violence. It’s all they’ve known.
Plus, they’re worse off after going to jail. They have a harder time finding housing or getting a job because of their record. If they were committing crimes because of a desperate living situation, and jail time just makes them more desperate, how can we possibly think that they’re going to be better off when they get released?
This is why looking at alternatives to a prison sentence is so important. The best justice programs are the ones that actually give the accused what they need to move forward.