California Penal Code 188

Such malice may be express or implied.  It is express when there is manifested a deliberate intention unlawfully to take away the life of a fellow creature.  It is implied, when no considerable provocation appears, or when the circumstances attending the killing show an abandoned and malignant heart.

When it is shown that the killing resulted from the intentional doing of an act with express or implied malice as defined above, no other mental state need be shown to establish the mental state of malice aforethought.  Neither an awareness of the obligation to act within the general body of laws regulating society nor acting despite such awareness is included within the definition of malice.