In American jurisprudence, an excuse is a defense to criminal charges that is a distinct from an exculpation. Justification and excuse are different defenses in a criminal case (See Justification and excuse). Exculpation is a related concept which reduces or extinguishes a person's culpability, such as their liability to pay compensation to the victim of a tort in the civil law.
 The excuse provides a mitigating factor for a group of persons sharing a common characteristic. Justification, as in justifiable homicide, vindicates or shows the justice. Thus, society approves of the purpose or motives underpinning some actions or the consequences flowing from them (see Robinson),[clarification needed] and distinguishes those where the behavior cannot be approved but some excuse may be found in the characteristics of the defendant, e.g. that the accused was a serving police officer or suffering from a mental illness. Thus, a justification describes the quality of the act, whereas an excuse relates to the status or capacity (or lack of it) in the accused. These factors can affect the resulting judgment which may be an acquittal, or in the case of a conviction may mitigate sentencing. An excuse may also be something that a person or persons use to explain any criticism or comments based on the outcome of any specific event.
 The executive and legislative branches of modern states enact policy into laws which are then administered through the judicial system. Judges also have a residual discretion to excuse individuals from liability if it represents a just result. When considering the consequences which are to be imposed on those involved in the activities forming the subject matter of the common law or legislation, governments and judges have a choice:
 To be excused from liability means that although the defendant may have been a participant in the sequence of events leading to the prohibited outcome, no liability will attach to the particular defendant because they belong to a class of person exempted from liability. In some cases, this will be a policy of expediency. Hence, members of the armed forces, the police or other civil organizations may be granted a degree of immunity for causing prohibited outcomes while acting in the course of their official duties, e.g. for an assault or trespass to the person caused during a lawful arrest or for an ambulance driver exceeding the speed limit in an emergency. Others are excused by virtue of their status and capacity. Others may escape liability because the quality of their actions satisfied a general public good. For example, the willingness to defend oneself and others, or property from injury may benefit society at large. Albeit that the actions of a vigilante fall outside the formal controls that would seek to ensure reasonable use of force in state-appointed police officers, such people may accidentally find themselves interrupting the commission of a crime and their actions in defence of their own or another's interests is justified out of expediency as opposed to having to wait until a police officer arrives before help can be rendered.  Whilst the jurisprudential importance of the distinction between justification and excuse defenses is clear, legally they have the same effect, acquittal, and there is an ongoing debate about whether the distinction makes any practical difference.
 An exculpation is a defense in which a defendant argues that despite the fact they committed and are guilty of the crime, tort, or other wrong and have a liability to compensate the victim, they should be exculpated because of special circumstances that operated in favor of the defendant at the time they broke the law.