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 Hawaii, as in many jurisdictions, 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 typically ranked from most to least blameworthy as follows: intentional, knowing, reckless, and criminal negligence. Under Hawaii law, a person is considered to act with criminal negligence when they fail to recognize a substantial and unjustifiable risk that their conduct may lead to certain circumstances or results. This risk must be so great that not perceiving it would be a significant deviation from the standard of care an ordinary person would exercise in the same situation. The concept of criminal negligence is such that the individual's failure to perceive the risk shows a disregard for the safety and welfare of others that goes beyond mere carelessness. In Hawaii, the specific mental state required for a crime is usually defined within the state's penal or criminal code, and the prosecution must prove the defendant possessed the requisite mental state to secure a conviction for the offense charged.