Implied malice has both objective and subjective components. The objective test requires “‘“an act, the natural consequences of which are dangerous to life … .”’” (People v. Knoller (2007) 41 Cal.4th 139, 143.) This means the act must carry “‘a high degree of probability that it will result in death.’” (Id. at p. 152.) The subjective test requires that the act be performed “‘“by a person who knows that his conduct endangers the life of another … .”’” (Id. at p. 143.) “In short, implied malice requires a defendant’s awareness of engaging in conduct that endangers the life of another—no more, and no less.” (Ibid; see also People v. Vasquez (2018) 30 Cal. App. 5th 786, 794 n.6; People v. Tseng (2018) 30 Cal.App.5th 117 [substantial evidence supported physician’s three convictions for second degree murder of patients who died from drug overdoses where the physician was aware her prescribing practices posed a risk of death].)
An unlawful killing without malice is involuntary manslaughter. (§ 192; see, e.g., People v. Blakeley (2000) 23 Cal.4th 82, 91; People v. Butler (2010) 187 Cal.App.4th 998, 1008–1009 [addressing the difference between implied malice murder and involuntary manslaughter]; CC 580.) “Generally, involuntary manslaughter is a lesser offense included within the offense of murder.” (People v. Gutierrez (2002) 28 Cal.4th 1083, 1145.) Accordingly, an instruction on involuntary manslaughter is required whenever there is substantial evidence indicating the defendant acted without conscious disregard for human life and did not form the intent to kill.
For example, in Vasquez the defense conceded that Vasquez administered a beating that killed the victim (Smith) but argued that Vasquez was not subjectively aware his actions could be deadly because Smith had a hidden spinal injury (metal rods had been placed in his neck in a prior surgery), the fatal injury was immediately adjacent to the metal rods, and the victim’s other injuries were relatively minor. The reviewing court concluded that refusal of the Vasquez’s instructional request was reversible error. (30 Cal. App. 5th 786, 789-90.)