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 term is used in Brian Forst's book Errors of Justice and in Robert Bohm's introduction to a special edition of The Journal of Criminal Justice on miscarriages of justice. If convicting an innocent person, called a miscarriage of justice, is a Type I error for falsely identifying culpability (a "false positive"), then an error of impunity would be a Type II error of failing to find a culpable person guilty (a "false negative"). Definition Forst divides errors of impunity into two categories. 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. About half of all felony victimizations in the U.S. are not reported to the police, and many of those that are reported are committed by skillful, elusive offenders. The second category consists of those errors that are real, unambiguous, significant, and avoidable. Examples include failures of the police to follow up leads to capture dangerous offenders and inmate escapees. Causes Errors of impunity can be caused in much the same ways as miscarriages of justice can, including, without limitation, the following: A skilled defense lawyer might be able to exploit a legal technicality in order to have crucial evidence ruled inadmissible. A skilled defense lawyer can make an otherwise credible witness lose his or her credibility by making the witness appear mentally incompetent in other aspects of his or her daily life (e.g. a person with autism might be labeled as mentally insane due to their neurological disorder, therefore questioning if the witness was having hallucinations). A type of legal immunity, such as diplomatic immunity or sovereign immunity. Corrupt judges, or detectives or other police officers, who can be bribed. Effects 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. As a result, Forst argues, the integrity of the justice system