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 Missouri, murder is classified into degrees, with first-degree murder being the most serious form of homicide. According to Missouri law, first-degree murder is when a person knowingly causes the death of another person after deliberation, which is the legal term for premeditation. Deliberation implies that the individual considered the act beforehand, reflecting a conscious decision to kill. This offense is punishable by death or life imprisonment without parole. Second-degree murder, on the other hand, is an intentional homicide without premeditation, or it can occur as a result of an underlying felony. Second-degree murder does not carry the death penalty but can result in a lengthy prison sentence. Missouri also recognizes the separate offense of capital murder, which includes specific aggravating circumstances that may make the offender eligible for the death penalty, such as killing a law enforcement officer or committing murder for hire. These distinctions are codified in the Missouri Revised Statutes, specifically in Chapter 565 concerning offenses against the person.