People v. Mehserle

California Court of Appeal, First Appellate District, Division One · 2012 · Evidence

206 Cal. App. 4th 1125 (2012)

Updated August 22, 2026

Evidenceinvoluntary manslaughtercriminal negligencepolice officerTaser-handgun confusionsufficiency of evidencenewly discovered evidenceEvidence Code section 352

Facts

While helping arrest Oscar Grant on a BART platform, defendant decided to use his Taser while Grant was prone on the ground and being restrained by another officer. Defendant instead drew his handgun from a different holster position, after several unsuccessful tugs, and shot Grant in the back. Defendant claimed he intended only to deploy his Taser and did not realize he had drawn his handgun until after the shot. The handgun and Taser differed markedly in color, weight, placement, and operation, and defendant had drawn his Taser twice earlier on the platform.

Issue

Whether substantial evidence supported the jury's finding of criminal negligence necessary for involuntary manslaughter, and whether the trial court erred in denying a new trial based on newly discovered handgun-Taser confusion incidents, excluding evidence of BART's postshooting remedial Taser policy changes, giving the challenged instructions, and denying probation.

Rule

In California, involuntary manslaughter based on a lawful act done without due caution and circumspection requires criminal negligence, meaning conduct that is a gross, reckless, or culpable departure from how an ordinarily prudent person would act under the same circumstances, creating a high risk of death or great bodily injury. The test is objective, not based on the defendant's actual awareness, and California recognizes no special heightened criminal-negligence standard for police officers. A new trial for newly discovered evidence is unwarranted if the evidence is cumulative or not likely to produce a different result, and marginally relevant evidence may be excluded under Evidence Code section 352.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In Sacramento, Officer Daniel Rios tried to subdue an unarmed nightclub patron who was face-down on the pavement while two other officers held the patron’s legs and shoulders. Rios announced he was going to use his electronic control device, but instead drew his black handgun from his right-side holster rather than the bright orange control device from his left-side cross-draw holster and fired one shot.

If Rios is charged with involuntary manslaughter based on criminal negligence, which is the strongest argument for affirmance of a conviction?

Explanation. Criminal negligence for involuntary manslaughter is judged by an objective standard: whether the defendant acted in a reckless way creating a high risk of death or great bodily injury and a reasonable person would have known of that risk. The majority rejected any special heightened standard for police officers and distinguished criminal negligence from subjective implied malice. A mistaken draw is not automatically excusable accident if the jury can find negligence from obvious weapon differences and the circumstances.