I think the thing that just about everybody gets wrong about criminal justice and how it should operate is also one of the more difficult aspects to fix through policy. Neither a broad philosophy of "tough on crime" nor a broad philosophy of leniency will ever work in practice. We have to deal with offenders one at a time.
In this case, I'm not going to dive into the obvious importance of due process and presumption of innocence. I'm only talking about people who are actually guilty of a crime. We can also get it out of the way that I don't think that people should be in prison unless there's a victim.
If there's one thing that I learned while working in the criminal justice reform space, it's that it's remarkable how people can turn themselves around. I've met murders who, after twenty-five years in prison, I would trust with my life. Their stories vary; but, a common thread was drug addiction. A significant number of people I met who were incarcerated have some story resembling being hooked on a drug, needing a fix and not having the money, and deciding to take a knife with them to meet the dealer.
What the tough on crime people miss is the aspect of rehabilitation. Some states like Texas are so focused on the punitive aspect of their justice system that they create repeat offenders. If you're released from prison in Texas and you don't have anybody to pick you up, they put you on a bus and drop you off at the stop nearest to where you were arrested with an amount of cash five dollars less than what you need to get an ID. I don't think anybody should be surprised that those people tend to end up back in prison.
Although there's some evidence of deterrence, there are diminishing marginal returns. One interesting bit of information is that, although there's no measurable correlation between states with the death penalty as opposed to states without and violent crime rates, the states that actually execute people tend to have lower murder rates than states that do have the death penalty and don't use it. That said, I still think that that's a thin argument because I don't think murders are looking up statistics.
The leniency side has its own problems. I have never been a big fan of tough "three strikes you're out" policies when it comes to repeat offenders. I know someone personally who spent a long time in prison after getting caught stealing a car the third time. Still, you can oppose those policies without blinding yourself to patterns. There are people who are broken machines. A guy with no criminal record who catches his wife on bed with his best friend and flies off the handle and kills somebody should spend a lot of time in prison; but, he's not likely to offend again. Austin Simon, the guy who was killed while assaulting Jose Alba, had twenty-seven arrests at the age of thirty-five. When you account for the time that he spent in jail or prison, that pretty much means that any time that he spent outside of the bars was spent finding ways to get back behind them. Nine of the twenty-seven arrests were for violent crimes, domestic violence, and one for assaulting a police officer. I'm not saying that Austin Simon would never have been able to get his act together if he hadn't gotten himself killed over a bag of chips; but, it seems irresponsible to set a man like that lose on the world without due diligence. If New York had given Simon a year in prison for each of his felony assault arrests, which seems like a fairly lenient number for violent assaults, he probably would have been in prison on July First rather than assassinating Alba.
The solution is simple while not being easy. We need to treat prisoners as individual human beings rather than trying to make blanket judgements based on what they did.
There are ways to make it easier though.
The most obvious is to end the war on drugs and mandatory minimum drug sentencing. I'm still haunted from meeting a woman who spent more time in prison than the murders a met because she dropped off a little baggy of meth when she was a teenager. You get the drug addicts out of prison and into rehab, there's less for the penal system to deal with. If we reduce the number of prisoners, we can place more focus on each individual prisoner who should actually be there.
I really do understand the reasoning behind both extremes. There's a simplicity to both; but, in my experience, simple solutions to complex problems are usually wrong. Right now, we have a system that's so thoroughly ripped in half by ideological strife that we have problems that are mirror images. We have people in the system that never should have been there and people rotting in prison who should have been out years ago. We also have people who should still be in prison who are roaming free looking for more victims. All the while, we have policy-makers who insist that the problems can be solved with simple platitudes - they can't.