For this reader, reporting has veered towards the salacious or sensational since Swiss authorities, acting on a request from the USA, arrested filmmaker Roman Polanski.

For those interested in the Polanski case, I recommend Roman Polanski: Wanted and Desired, a 2008 documentary; I thought it demolished the credibility of the prosecutor and judge, but did not paint Polanski sympathetically.

We in Europe risk losing a chance to learn from what this case can teach us about two American imports: plea bargaining and sentencing guidelines.

Polanski engaged in sexual activity with a minor under the age of consent. This is a criminal offense. In the Polanski case, the underlying facts seem not to have been seriously contested. Prosecutors initially “threw the book” at Polanski, charging him with several grave offenses. Rather than defend himself against all charges in court, Polanski chose to enter a guilty plea to a lesser offense. He made this choice because the authorities agreed that he would not suffer imprisonment.

This is plea bargaining. It’s common –more the rule than the exception– in the United States, and is viewed in France favorably, as a way to speed the administration of justice and to relieve court congestion. In the Polanski case, there is a problem because the defendant claims that prosecutors and the court broke or intended to break their promise.

What recourse does a defendant have when authorities breach a plea bargain? This is an interesting question. It deserves attention and discussion.

At the time of the Polanski case, judges had considerable latitude in sentencing convicted defendants. They considered, among other points, the personal history and background of the defendant. Polanski’s history is exceptional, and could support arguments that he not be imprisoned.

Many today are surprised or offended that someone convicted of sexual activity with a minor under the age of consent would not face serious punishment, such as imprisonment. These reactions and observed disparities in treatment (in other words, a given offense could result in very different penalties) led in the decades since the Polanski case to sentencing guidelines. These guidelines, enacted by the legislature, limit the discretion available to judges when sentencing convicted defendants.

Two kinds of sentencing guidelines stand out and deserve special mention. The first is minimum sentencing, where the convicted must serve a minimum prison term. The second is penalty enhancement for recidivists, where repeat offenders are sanctioned more severely; this is best illustrated by California’s “three-strikes-you’re-out” policy, where recidivists faced imprisonment for life. Both of these measures tend to increase prison populations. They may also bloat the number of prisoners serving very long sentences. (If a small population commits most criminal offenses, then it’s possible that the prison population would decrease but include a larger share of detainees serving long sentences.) In many cases, they will also increase a defendant’s interest to enter into a plea bargain.

What cost should society bear in order to build and maintain prisons? In France, prisons are universally recognized as being overcrowded and poorly maintained. Considerably efforts are needed to bring the status quo to an acceptable position; even greater efforts would be needed to accommodate recidivists if, as many French people argue, they were sentenced more harshly. These questions also deserve attention and discussion.