What factors must a jury consider when deciding whether to convict a man of murder for strangling his sleeping victim?

premeditation, deliberation and willfulness. (See People v. Shamblin (2015) 236 Cal.App.4th 1, 11-12 [length of time it took to strangle victim indicated defendant had ample time to consider the consequences of his actions].) Moreover, "[t]he utter lack of provocation by the [sleeping] victim is a strong factor supporting the conclusion that appellant's attack was deliberately and reflectively conceived in advance." (Lunafelix, supra, 168 Cal.App.3d at p. 102.)

Appellant argues the trial court had a duty to sua sponte instruct the jury on the lesser included offense of involuntary manslaughter in relation to the murder charge. "Involuntary manslaughter is 'the unlawful killing of a human being without malice aforethought and without an intent to kill.' [Citation.] A verdict of involuntary manslaughter is warranted where the defendant demonstrates 'that because of his mental illness . . . he did not in fact form the intent unlawfully to kill (i.e., did not have malice aforethought).' [Citation.] An instruction on involuntary manslaughter is required whenever there is substantial evidence indicating the defendant did not actually form the intent to kill. [Citations.]" (People v. Rogers (2006) 39 Cal.4th 826, 884 (Rogers), italics omitted.)