In what circumstances will a jury be instructed to find a defendant guilty of voluntary manslaughter?

In Genovese, the defendant challenged the voluntary manslaughter instruction in the same fashion defendant does now. (People v. Genovese, supra, 168 Cal.App.4th at p. 825.) The jury in Genovese was instructed with the same principles of murder and voluntary manslaughter as defendant's jury was instructed. The Genovese jury was told " '[a] killing that would otherwise be murder is reduced to voluntary manslaughter if the defendant killed someone because of a sudden quarrel or in the heat of passion.' " (Id. at p. 831.) Based on this language the court explained as follows: "The killing could not 'otherwise be murder' unless the jury found defendant intended to kill the victim or acted with conscious disregard for human life, and the jury was so informed in the instruction defining murder (i.e., that to prove murder, the prosecution must prove defendant acted with malice aforethought, and there are two kinds of malice aforethought -- express, which requires intent to kill, and implied, which requires conscious disregard for human life)." (Id. at pp. 831-832.) The court rejected the defendant's argument that, once the jury determined express or implied malice was present, it was not told it could still find the defendant guilty of voluntary manslaughter if it believed he acted in the heat of passion. The court noted the plain language of the instructions informed the jury that a killing that would otherwise be murder is reduced to voluntary manslaughter if the defendant acted on a sudden quarrel or in the heat of passion. (Id. at p. 832.)

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