The defendant cannot be guilty of manslaughter by committing a merely negligent act or if the killing was either justifiable or excusable homicide, as I have previously instructed you.
In the event of any reinstruction on manslaughter, the instructions on justifiable and excusable homicide as previously given should be given at the same time.
Early American cases on the criminal law reproduced these common law distinctions between justifiable and excusable homicide. In one of the earliest recorded criminal cases in the United States, a judge instructed a New Jersey jury "that homicide was, in some cases, justifiable, and in others was excusable...." (68) In "the most important murder trial of the early republic," (69) the 1806 Massachusetts case of Commonwealth v.
(75) Justifiable homicide was the work of the sovereign, directly or indirectly, for "the law mu[s]t require [the homicide] otherwise it is not justifiable"; (76) excusable homicide, by contrast, was the work of the great universal "principle of [s]elf-pre[s]ervation." (77) Whatever the common consequence to the alleged offender, the two forms of homicide were conceptually distinct.
On the other hand, an "excusable homicide" occurs when "a man must protect himself from an assault or the like, in the course of a sudden brawl or quarrel, by killing him who assaults him." (80) Blackstone explains that where "the slayer has not begun the fight, or (having begun) endeavors to decline any further struggle, and afterwards, being closely pressed by his antagonist, kills him to avoid his own destruction, this is homicide excusable by self-defence." (81) In this case, the person claiming self-defense "should have retreated as far as he conveniently or safely can, to avoid the violence of the assault, before he turns upon his assailant ..." (82)
Blackstone describes two species of "Excusable Homicide." The first is akin to manslaughter and its varying degrees, and will not be discussed here.
You can read the excusable homicide statutes that are present in many states today and immediately see the echoes of that 1532 Parliamentary act, such as California's excusable homicide statutes: "When committed by accident and misfortune, in the heat of passion, upon any sudden and sufficient provocation, or upon a sudden combat, when no undue advantage is taken, nor any dangerous weapon used, and when the killing is not done in a cruel or unusual manner." (4) There's one thing that you will notice is missing here: the duty to retreat before using deadly force.
The decision is 'a bit complicated, but among other concerns that the Idaho Supreme Court expressed was that this jury instruction was defective--that a person was not required to retreat out of one's home to take advantage of the excusable homicide defense.
The defendant cannot be guilty of in manslaughter if the killing was either justifiable or excusable homicide
, as I have previously instructed you.