Mental states that determine the degree of guilt or culpability in criminal law are generally classified from highest (most worthy of blame or punishment) to lowest as: (1) intentional; (2) knowing; (3) reckless; and (4) criminal negligence.

A person acts with criminal negligence, or is criminally negligent, with respect to circumstances surrounding his conduct or the result of his conduct when he ought to be aware of a substantial and unjustifiable risk that the circumstances exist or the result will occur. The risk must be of such a nature and degree that the failure to perceive it constitutes a gross deviation from the standard of care that an ordinary person would exercise under all of the circumstances, as viewed from the accused person’s standpoint at the time of the alleged criminal negligence.

Criminal offenses or crimes often specify the culpable mental state the prosecution is required to prove to convict a defendant of the offense. These culpable mental states are generally defined in the relevant state or federal statutes—usually in the penal or criminal code.

In New Jersey, as in many jurisdictions, the mental state of an individual at the time of committing a crime is crucial in determining their degree of guilt or culpability. The mental states are ranked from most to least blameworthy: (1) intentional, (2) knowing, (3) reckless, and (4) criminal negligence. Criminal negligence in New Jersey is defined as failing to perceive a substantial and unjustifiable risk that results in a gross deviation from the standard of care an ordinary person would exercise. This risk must be apparent and significant enough that not noticing it would be a considerable departure from what is expected of an average person in the same situation. New Jersey's criminal statutes, particularly within the New Jersey Code of Criminal Justice (Title 2C of the New Jersey Statutes), outline the necessary mental states required for various offenses. To secure a conviction, the prosecution must prove that the defendant acted with the specified culpable mental state as defined by the relevant statute.