Murder is the intentional, premeditated killing of another human being. The premeditation requirement for murder was historically described in the law as “malice aforethought.”

Laws regarding murder vary from state to state, and some states have a separate criminal offense of capital murder, which usually involves the most egregious circumstances, such as killing a peace officer in the line of duty or lying in wait to ambush and kill the victim. Capital murder offenses carry a potential death penalty.

And some states use the distinction of first degree murder (done with premeditation and punishable by death or life in prison) and second degree murder (generally an intentional killing without premeditation—also known as manslaughter or voluntary manslaughter in some states).

The criminal offense of murder is generally located in a state’s statutes—often in the penal or criminal code.

In Illinois, murder is defined under Illinois Compiled Statutes (720 ILCS 5/9-1) as the intentional or knowing killing of another person without lawful justification, and with either the intent to kill or do great bodily harm, or with the knowledge that the actions create a strong probability of death or great bodily harm. Illinois law distinguishes between first-degree and second-degree murder. First-degree murder involves premeditation and intent, and it is punishable by a range of sentences including life imprisonment. Second-degree murder, on the other hand, is an intentional killing without premeditation, often occurring in the heat of passion provoked by the victim, and carries a lesser sentence. Illinois does not have a separate offense of 'capital murder,' and it abolished the death penalty in 2011. Therefore, the most severe punishment for first-degree murder in Illinois is life imprisonment without the possibility of parole.