In all these discussions pitting innocent men getting imprisoned vs guilty men going free, one factor rarely ever comes up: innocent men (and women and children) who fall victim to crime.<p>IMO, one of the most valuable roles of the justice system is to be a deterrent. <i>&quot;If you commit a crime, you will be put in jail, so don&#x27;t even think about it.&quot;</i> If you&#x27;ve ever witnessed schoolyard bullying in action, that&#x27;s exactly what every single day in adult life would also look like, if not for the justice system. By deterring would-be-criminals, it keeps innocent people safe, without even having to send the would-be-criminals to jail.<p>Except that it isn&#x27;t a perfect deterrent. Crime is still a major factor in society. To give just one example, 20% of women in America experience sexual assault at some point in their lives. And then there&#x27;s robbery, assault, manslaughter, homicide... Some crimes are committed by those who&#x27;re mentally unstable, or in the heat of the moment. But the vast majority are committed by criminals who are fully aware of what they are doing. People who would never do it if they knew for sure they would go to jail, but think they have a good enough chance of getting away with it. They either think they won&#x27;t get caught by the police, or even if they did get fingered, they can find some loophole or weakness in the prosecution&#x27;s case that would enable them to beat the rap. And the likelihood of the latter really comes down to how high the burden of proof is. A guilty person is much more likely to get convicted in a legal system where &quot;n = 5&quot;, as opposed to &quot;n = 10.&quot;<p>Psychology studies show that punishments are most effective as deterrents when they are consistent, immediate and guaranteed. The greater the variance, the better the chances of someone getting away with it, the less powerful the deterrent effect will be. Which means you&#x27;re going to have more victims of crime. More victims of assault, kidnappings, rape and murder.<p>Which is really what the trade off should be all about. <i>&quot;It&#x27;s better that N innocent people fall victim to crime, than for 1 innocent person to go to jail.&quot;</i> Now what would your answer for N be?