The unlawful killing of a human being without malice or premeditation, either express or implied; distinguished from murder, which requires malicious intent.
The distinctions between manslaughter and murder, consists in the following: In the former, though the act which occasions the death be unlawful, or likely to be attended with bodily mischief, yet the malice, either express or implied, which is the very essence of murder, is presumed to be wanting in manslaughter. It also differs from murder in this, that there can be no accessaries before the fact, there having been no time for premeditation. Manslaugbter is voluntary, when it happens upon a sudden heat; or involuntary, when it takes place in the commission of some unlawful act.
The cases of manslaughter may be classed as follows those which take place in consequence of: 1. Provocation. 2. Mutual combat. 3. Resistance to public officers, etc. 4. Killing in the prosecution of an unlawful or wanton act. 5. Killing in the prosecution of a lawful act, improperly performed, or performed without lawful authority. The provocation which reduces the killing from murder to manslaughter is an answer to the presumption of malice which the law raises in every case of homicide; it is therefore no answer when express malice is proved and to be available the provocation must have been reasonable and recent, for no words or slight provocation will be sufficient, and if the party has had time to cool, malice will be inferred. In cases of mutual combat, it is generally manslaughter only when one of the parties is killed. When death ensues from duelling the rule is different, and such killing is murder. The killing of an officer by resistance to him while acting under lawful authority is murder; but if the officer be acting under a void or illegal authority, or out of his jurisdiction, the killing is manslaughter, or excusable homicide, according to the circumstances of the case. Killing a person while doing an act of mere wantonness, is manslaughter as, if a person throws down stones in a coal-pit, by which a man is killed, although the offender was only a trespasser.
When death ensues from the performance of a lawful act, it may, in consequence of the negligence of the offender, amount to manslaughter. For instance, if the death has been occasioned by negligent driving. Again, when death ensues, from the gross negligence of a medical or surgical practitioner, it is manslaughter.