What is justice?
This question is important, because the goal of a system of justice is dependent on what we mean when we say "justice." Do we mean punishment? Vengeance? If so, then the current American system of justice is perfectly fine, and nothing I have to say here is of any value whatsoever.
I don't think that's true, though. I think that justice (defined as "morally right and fair behavior or treatment") often has very little to do with the system of criminal courts and incarceration in the United States. As Libertarians, we already have a standard for "morally right and fair:" Don't hurt people. Don't take their stuff. A just system, then, would be one which protects people from being hurt and having their stuff taken.
This can be accomplished by putting everyone in a bubble suit in a locked room. Now they're safe!
Obviously that's not the goal. A system which limits the liberty of the people whose liberty it is meant to protect is not a very well-designed system. What, then, should this system do, to protect the life, liberty, and property of the people?
There are five recognized purposes of a system of criminal punishment: Deterrence, retribution, rehabilitation, incapacitation, and restitution. Let's examine them each in turn.
Deterrence is the idea that by imposing harsh penalties for crime, potential criminals will be dissuaded from committing crimes for fear of the punishment this will incur. This is a popular refrain among conservatives who favor harsher sentences. However, there is one glaring problem with this theory: It doesn't work. Even the government admits this; the National Institute for Justice, the research branch of the Department of Justice,
points out that prison sentences, harsher penalties, and even the risk of execution do not deter crime. Criminals don't often weigh the possible punishments should they be caught; instead, they weigh how likely they are to be caught. The only effective deterrence is a visible police presence that affects this perception. To impose cruel and unusual punishments in the hope - especially the vain hope - that it will somehow dissuade others from criminal acts seems to me to be completely unrelated to the idea of justice.
Retribution is the familiar "eye for an eye, tooth for a tooth" Old Testament theory of justice. A thief must be stolen from; a murderer must be murdered; a rapist must be raped. The object is to expiate the guilt of the offender by imposing on them the same suffering they imposed on their victim. There is one immediate objection I have to this idea; it is that harming someone does nothing to make whole the harm that another has suffered. To libertarians, who hold that force must only be used in defense, the idea of intentionally using force in this manner must be particularly onerous, in the same manner as torture. In preventing harm, one may use as much force as is required; this is defense. To use force afterwards, because of anger, is not defense.
Rehabilitation is the idea that offenders can be induced to change their behavior through various methods. There is one notable difference between rehabilitative punishment and deterrent or retributive punishment: It can be proven to work. In fact, the components of successful rehabilitation programs can be measured, and the results used to improve future iterations. Rehabilitation is effective at reducing recidivism. However, there is a flaw in a system which focuses solely on rehabilitation: The system cannot rehabilitate an offender who does not wish to be rehabilitated. And so a rehabilitation-focused system of punishment must either release unrehabilitated offenders when their sentence has expired, or detain them indefinitely until it is satisfied that they have been rehabilitated. We can see the results of the second in California with indefinite civil commitment, a system in which offenders who have completed their sentence are simply moved to another facility from which they are never released.
Incapacitation is the idea that repeat offenders should be incarcerated for long periods of time in order to prevent them from offending again. On its face, it seems like a great idea - we'll be removing career offenders from the public, which will reduce crime! In action, what happens is varying definitions of "repeat offenders" - such as the notorious three-strikes law, which can impose life sentences for nonviolent or low-level crimes.
Restitution is related to the Biblical concept of retribution, with one important difference: In retribution, both the victim and the offender are harmed. In restitution, the offender makes whole the victim. This satisfies pretty much every definition of justice, and is, in my opinion, the best option when it is feasable.
But what about when it isn't? What if the offender cannot afford restitution? What if the victim cannot be made whole, as in cases of rape, murder, or grievous assault?
That is where we must look to the other four methods. The first two I reject out of hand; deterrence because it is ineffective, and retribution because it violates the liberty principle to use force only in defense. Rehabilitation is possible for those who are willing to change their behavior, but there will always be those who refuse, who perhaps do not even admit that their actions are harmful. Incapacitation works only insofar as the person who harms another must be prevented from doing so again, and not as a predictor of future harm - there are too many people incarcerated right now for repeated crimes of poverty under this idea.
When we list the basic human rights of life, liberty, and property, we list them in this order not only in mere imitation of Thomas Jefferson, but because this is the order in which we value them. And when a person must be deprived of their rights in order to protect the rights of another, this order again comes into play; we do not deprive an individual of his life because he deprived someone of their property. Theft is not a capital crime. And so we should apply this same hierarchy to the theory of criminal justice.
An offender who violates a person's right to property may rightly be liable to have his own right to property curtailed to make whole the victim: a thief may be required to repay what he has stolen. This is restitution, and it should be the default response to nearly all property crime.
An offender who violates a person's right to liberty or who threatens their life may rightly have their own liberty curtailed to prevent them from victimizing another: kidnappers, rapists, violent assaulters, and murderers may be incarcerated to prevent them from harming people. In these cases, often no restitution is possible.
However, the purpose of the incarceration should not be retribution. It should not be deterrence. It should be to prevent the offender from harming others. To this end, the offender should be incarcerated only so long as they are a risk to the public. The violent young man who "ages out" of his tendency for violence after the age of 25, the old man who is crippled and no longer capable of it - neither of these should be incarcerated.
To incarcerate someone who poses no threat to the public is not justice or liberty. Only those who can be proven a threat should be incarcerated. This is the purpose of the sentencing phase of the criminal trial; after guilt or innocence has been determined, the proper treatment should be determined. Too often the sentencing phase is merely a formality, where a prosecutor argues for longer sentences and the defense argues for shorter sentences, which are imposed by a judge with little to no regard for the actual safety of the public, but rather to sate their desire for vengeance. And that is injustice.