US Criminal Law/Summary

Constitution of the United States, page 1.jpg


Scale of justice 2.svg
US Supreme Court.JPG

Liability of omissions

In criminal law, people may be guilty of a crime based on their failure to act. For example, for failing to stop or report sexual abuse; also, one's failure to report a felony may be a criminal act. A person may also be charged with conspiracy unless he completely and voluntarily renounces participation in that conspiracy. This is a slightly different operation of criminal guilt by omission because the actor is engaged in a conspiracy until he completely and voluntarily renounces his participation. In some jurisdictions, the person may avoid criminal liability by stopping the conspiracy from achieving its aims.


Recklessness is one of the three mental states that constitute mens rea. Recklessness shows less culpability than intention and knowledge, but more culpability than criminal negligence. The test of any mens rea element is always based on an assessment of whether the accused had foresight of the prohibited consequences and desired to cause those consequences to occur.

The three types of test are:

  • subjective where the court attempts to establish what the accused was actually thinking at the time the actus reus was caused;
  • objective where the court imputes mens rea elements on the basis that a reasonable person with the same general knowledge and abilities as the accused would have had those elements; or
  • hybrid, i.e. the test is both subjective and objective.

The most culpable mens rea elements will have both foresight and desire on a subjective basis. Recklessness usually arises when a person is aware of the potentially adverse consequences to the planned actions, but chooses to proceed anyway, exposing others to the risk of suffering the foreseen harm but not actually desiring that the victim be hurt.

Strict liability

In general, strict liability is rarely imposed in criminal law. There has been some debate regarding strict liability for criminal offenses, as it removes the mental state (mens rea) as an element of the offense. Several strict liability criminal offenses, however, have been widely approved, such as driving while intoxicated and speeding. The basic point (and underlying societal judgment) is that proof of the act itself beyond a reasonable doubt is sufficient to show criminality.

Similarly, in civil law, strict liability will be imposed when an act is itself so hazardous to the community that intent is not a factor in determining if the perpetrator is to be held to account. If one engages in blasting and damages another's property it does not matter that there was no intention to do damage, nor that great care was exercised in planning and executing the blasting, the person doing the blasting is liable.


In criminal law those who can be held accountable are those who perpetrate the unlawful act (the perpetrator), and those who somehow aid, promote or encourage the unlawful act (an accessory or aider and abetter). To be guilty as an "aider and abetter" one must somehow, with knowledge of the unlawful purpose of the perpetrator, aid promote or encourage the act. Both then are principals in the act and can each be held accountable for the acts of the other.

A common example is the robbery and get away driver. Both are principals. If the inside man shot someone in the course and scope of the robbery, the get away driver is also responsible for the shooting, even though he never anticipated the shooting. Principals of Conspiracy permeate this concept.