Under what circumstances must a jury consider a charge of manslaughter based on heat of passion?

"[A] trial court must instruct the jury sua sponte on an uncharged offense that is lesser than, and included in, a greater offense with which the defendant is charged only if there is substantial evidence that, if accepted, would absolve the defendant from guilt of the greater offense but not the lesser." (People v.. Waidla (2000) 22 Cal.4th 690, 737, 94 Cal.Rptr.2d 396, 996 P.2d 46.) "'"Substantial evidence is evidence sufficient to 'deserve consideration by the jury, ' that is, evidence that a reasonable jury could find persuasive." [Citation.]' [Citation.]" (People v. Cunningham (2001) 25 Cal.4th 926, 1008.) This sua sponte duty exists even if the lesser offense is inconsistent with the theory of defense elected by the defendant or the defendant specifically requests that the jury not be instructed on lesser included offenses. (People v. Breverman, supra, 19 Cal.4th at pp. 154-155.)

"The heat of passion requirement for manslaughter has both an objective and a subjective component. [Citation.] The defendant must actually, subjectively, kill under the heat of passion. [Citation.] But the circumstances giving rise to the heat of passion are also viewed objectively." (People v. Steele (2002) 27 Cal.4th 1230, 1252.) Thus, heat of passion, in this context, "'must be such a passion as would naturally be aroused in the mind of an ordinarily reasonable person under the given facts and circumstances, ' because 'no defendant may set up his own standard of conduct and justify or excuse himself because in fact his passions were aroused, unless further the jury believe that the facts and circumstances were sufficient to arouse the passions of the ordinarily reasonable man.'" (Id. at pp. 1252-1253.)