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 California, murder is defined as the unlawful killing of a human being with malice aforethought, as per the California Penal Code. The state distinguishes between first-degree and second-degree murder. First-degree murder includes killings that are willful, deliberate, and premeditated, or that occur during the commission of certain felonies. It is punishable by death, life in prison without the possibility of parole, or 25 years to life in prison. Second-degree murder encompasses killings that are intentional but not premeditated or deliberate, and the punishment is generally 15 years to life in prison. California also recognizes the special circumstance of capital murder, which includes particularly egregious acts such as the murder of a law enforcement officer or murder for financial gain, and can result in the death penalty or life in prison without the possibility of parole. It's important to note that California currently has a moratorium on executions, although the death penalty remains a legal sentence.