Currently before Congress is a piece of legislation known as “Kate’s Law,” which has ignited both a media firestorm and a long-overdue conversation about modern ideas of criminal punishment.

The law is named for Kate Steinle, who was shot on San Francisco’s popular Pier 14 in July 2015. Kate was allegedly shot by a seven-time convicted felon and five-time deportee named Francisco Sanchez. Sanchez confessed to shooting Steinle during a televised interview.

The major focus of media coverage has been San Francisco’s “sanctuary city” policy, which prohibits city police from inquiring about the immigration status of criminal detainees. Kate’s Law aims to deter deportees from returning by increasing mandatory minimum prison sentences for felony reentry. Those convicted of reentry would automatically serve at least five years in federal prison. But who cares about longer prison sentences?

Taxpayers care, because they have to foot the bill. Police care, because they are often the first to see the effects of long prison sentences on community stability. And politicians care, because nobody ever lost an election by being too tough on crime. But criminals simply don’t care.

Over the last twenty-five years, as mandatory minimums have been applied with a heavy and profligate hand, analysis has repeatedly shown that they have a limited effect on crime prevention. According to a 2011 study by the Iowa Department of Corrections, mandatory minimum sentences for drug traffickers resulted in higher recidivism rates than waived sentences, probation, and rehabilitation. A statement by the United States Sentencing Commission in 2013 found that mandatory minimums were inconsistently applied, unfairly imprisoned large numbers of first-time and low-level offenders and had no effect on reducing repeat offenders.

Mary Looman, a psychologist for the Oklahoma Department of Corrections, has said that “[i]n many poor neighborhoods, so many people are in prison that it often may seem more like a rite of passage than a punishment.” Research in South Texas has shown that prison provides a haven within which gangs can complete the indoctrination of new members. A prison sentence makes a person “bad” and someone to be feared, especially with the weight of a gang or cartel behind them. The longer the sentence, the badder the “vato.”

It is clear from decades’ worth of research that long prison sentences do not prevent crime. Prison is not a deterrent. It’s horrible, it’s terrifying, but often not so very different from the lives prisoners were living before their convictions. Francisco Sanchez was a homeless drug dealer living on the streets of San Francisco. He has survived five trips across the hostile deserts of northern Mexico to cross the border and at least twenty years in U.S. prisons serving twelve different sentences. He doesn’t fear prison, it’s just one more tour “inside.”

The purpose of prison, or really any other sentence, is to be a deterrent. It makes a person afraid of the consequences of being caught. In balancing the intricacies of the Eighth Amendment, we have created an impossible situation in which criminals no longer fear the consequences of their actions and the criminal justice system no longer commands respect (if it ever did). Physical punishment doesn’t stop crime either, as has long been trumpeted by opponents of the death penalty. Putting people in prison will not stop them from trying to get into the United States illegally, from selling drugs or from committing any other crime.

The change has to arise out of the psychology of crime itself. As long as crime makes you “bad,” and “bad” is a term of respect, the criminal is king. As long as poverty and poor education combine to fracture communities, and people seek affirmation in deference, there is no sentence that will deter them from trying to succeed in the only way they know. Because what does a person who has nothing have left to lose? How to make criminals truly penitent rather than resentful of the people that punish them? These are the important questions that require careful, considered and reasoned approaches to criminal justice reform- not simply slapping a few more years onto a prison sentence and putting up a memorial on Pier 14.