Evidence: Exclusion of Marijuana Use

Hernandez v. County of Los Angeles, (Second District, June 17, 2014) 226 Cal.App.4th 1599, 173 Cal.Rptr.3d 226.

The daughter of a man who was killed when he was struck by a Los Angeles County Deputy Sheriff’s car while standing near his car after an accident on the freeway,  brought a wrongful death action against the deputy and the County of Los Angeles. Prior to trial the plaintiff filed a motion in limine to exclude evidence of her father’s use of medical marijuana, contending that the County could not show the decedent was impaired by marijuana at the time of the accident or establish any causal connection between his marijuana use and his death, and that the evidence would be unduly prejudicial.

The trial court denied the motion, concluding that evidence of whether the decedent was impaired and whether such impairment contributed to the collisions or his actions, was relevant to assess fault attributable to him. The jury returned a verdict in favor of the plaintiff but apportioned 14 percent of the fault to the decedent. The court of appeal reversed and remanded the case for a new trial, concluding that “evidence of marijuana use is irrelevant in the absence of a causal connection between the marijuana use and the accident”:

Because the experts could not identify any manner in which marijuana use contributed to the accident that injured Randy or his decision to exit the Land Rover, the evidence was not relevant to the issues and had no probative value. Even if the presence of marijuana in Randy’s blood had some minimal probative value, the danger of undue prejudice was substantial. The conflicting evidence about marijuana use confused the issues for the jury and encouraged them to speculate whether marijuana use was a factor in the accident in some way, when there was no evidence to support causation. The County’s attorney even used the marijuana evidence to suggest that Randy might not have had a legitimate medical need for marijuana or that marijuana was not a legitimate treatment option. This was impermissible character evidence that had nothing to do with negligent actions on the morning that Randy was killed, because Randy’s character was not at issue. …

None of the cases relied on by the County directly considered whether evidence of drug use is admissible without evidence of causation. …  These cases concerned alcohol, which is available for adults to purchase without a prescription, and did not necessarily require expert testimony as to the probable effects. Unlike alcohol, medical marijuana is not generally available for purchase by the public and expert testimony is required to show the effects of marijuana. Authorities in other jurisdictions have concluded drug evidence is not relevant or is more prejudicial than probative, in the absence of a link between the evidence and the cause of the accident, and that the admission of drug evidence in the absence of causation is prejudicial. … The evidence of drug use was substantially more prejudicial than probative, and it is reasonably probable the judgment would have been more favorable to Jocelyn in the absence of the evidence about Randy’s use of marijuana.