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 Arizona, the mental state of an individual plays a crucial role in determining their degree of guilt or culpability in criminal law. The mental states are ranked from most to least blameworthy as follows: (1) intentional, (2) knowing, (3) reckless, and (4) criminal negligence. Criminal negligence in Arizona is defined as failing to perceive a substantial and unjustifiable risk that a reasonable person would have recognized, which represents a gross deviation from the standard of care expected in the situation. This risk must be apparent and significant enough that not noticing it would be considered a major departure from what an ordinary person would do. For a defendant to be convicted of a crime, the prosecution must prove the defendant acted with the culpable mental state as specified by the relevant statute. These mental states are typically outlined in the Arizona Revised Statutes, particularly in the criminal or penal code.