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 Nebraska, 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. For a person to be found criminally negligent in Nebraska, they must have failed to perceive a substantial and unjustifiable risk that their conduct would lead to certain circumstances or results. This risk must be so great that not recognizing it would be a significant departure from what an ordinary person would do under the same conditions. Nebraska's criminal statutes, which can be found in the state's penal code, define these mental states and set forth the specific mental state required for each offense. To secure a conviction, the prosecution must prove that the defendant acted with the requisite level of culpability as defined by the relevant law.