An error of impunity is a lapse in the justice system that results in criminals either remaining at large or receiving sanctions that are below a socially optimal level.
The first category consists of those that are like car accidents: the community may be able to do more to prevent them, but generally prefers to consider that doing so is beyond the reach of the criminal justice system.
Examples include failures of the police to follow up leads to capture dangerous offenders and inmate escapees.
Errors of impunity can be caused in much the same ways as miscarriages of justice can, including, without limitation, the following: Forst argues that a variety of social costs are incurred as the number of culpable offenders set free increases: public safety and the quality of life are compromised, the credibility of deterrent effectiveness is lost, and citizens become increasingly inclined to perceive injustices to victims and alienation from the police and courts, if not from government generally.
These lapses can run through the entire justice system, from ineffective policing and prosecution to weak sentencing and corrections.