What is the test for instructing a jury on voluntary manslaughter?

The trial court must instruct on lesser included offenses only if the accused proffers evidence sufficient to "deserve consideration by the jury, i.e. 'evidence from which a jury composed of reasonable men could have concluded' " that the particular facts underlying the instructions did exist. (People v. Flannel (1979) 25 Cal.3d 668, 684, 160 Cal.Rptr. 84, 603 P.2d 1, quoting from People v. Carr (1972) 8 Cal.3d 287, 294, 104 Cal.Rptr. 705, 502 P.2d 513.)

Voluntary manslaughter is statutorily defined as the unlawful killing of a human being upon a sudden quarrel or heat of passion. (Pen.Code, 192, [185 Cal.App.3d 693] subd. (a).) "If a killing, even though intentional, is shown to have been committed in a heat of passion upon sufficient provocation the absence of malice is presumed. [Citation.] [p] ... Because the existence of malice is presumed when the circumstances of a killing suggest an intent to kill ... provocation and heat of passion must be affirmatively demonstrated. [Citations.]" (People v. Sedeno (1974) 10 Cal.3d 703, 719, 112 Cal.Rptr. 1, 518 P.2d 913, disapproved on other grounds in People v. Flannel, supra, 25 Cal.3d 668, 160 Cal.Rptr. 84, 603 P.2d 1, italics in original.)