There are two types of intentional homicide: manslaughter and murder. Although murder was not graded at common law, most states differentiate between first and second degree murder.
Murder is the commission of homicide with malice aforethought. See also, MPC § 210.2(l)(a). Malice aforethought denotes purpose and intent, as opposed to accident and mischance. It may be express or implied.
a. Second Degree Murder
Until there is proof of an aggravating or mitigating factor, all intentional homicides are classified as second degree murder.
b. First Degree Murder
Upon proof of premeditation, second degree murder becomes first degree murder.
Manslaughter is intentional homicide committed without malice. Proof of provocation or extreme emotional disturbance reduces intentional homicide from murder to manslaughter.