In California, homicide offenses are divided into distinct categories based on the defendant’s mental state, intent, and the surrounding circumstances of the killing. Among the most serious distinctions in criminal law is the difference between first-degree murder and second-degree murder. While both offenses involve the unlawful killing of another human being with “malice aforethought,” the legal differences between them can significantly impact how a case is charged, defended, and ultimately punished.
The Legal Definition of Murder
Under California Penal Code § 187, murder is defined as the unlawful killing of a human being with malice aforethought. Malice can be either express or implied. Express malice refers to a deliberate intention to take a life, whereas implied malice exists when a person engages in conduct that shows a conscious disregard for human life.


