CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Opinion & Scientific Evidence
......Content of Expert Opinion
.........Inadmissible Matter; Method
18 Cards On This Topic:

Court did not err in excluding expert testimony based on dissimilar animal studies and questionable epidemiological works re connection of PCB exposure to lung cancer.

No abuse of discretion in excluding D's proffered expert testimony in mitigation of death sentence, directed at nonexistent "misperceptions" jurors might have about LWOP.

E's testimony, that "exhaust vent" atop water heater may have been dislodged and caused fatal CO leak, inadmissible on grounds it was unduly speculative, based on unreliable hearsay, and w/out adequate foundation.

Trial ct. applied incorrect standard by requiring E to be "100 percent certain" D would not commit a violent act under any circumstances before proffered testimony could be admitted.

Although not appropriate for testifying expert to recount details of the another doctor’s report or expression of opinion, even if error here, not prejudicial.

Gang expert simply informed jury how he felt case should be resolved based on D being gang member with weapons in gang territory—an improper opinion which could not provide substantial evidence to support gang enhancement.

Although P's experts should not have testified in detail from Atascadero State Hosp. records, error harmless where trial court gave limiting instructions and most of Es' information was testified to by D.

Trial court did not abuse its discretion in admitting testimony of DA's gang expert re Mexican Mafia in attempted killing of rival gang member in jail—D's intent was not subject of expert's testimony.

Trial court did not abuse its discretion in excluding deceased expert's opinion as to D's speed under guise of second expert having relied on deceased expert's report.

Expert witness declarations regarding school's security measures were properly excluded in student injury case where they were speculative and conjectural and couldn't establish causation.

Testimony of police street gang expert about D's subjective knowledge and intent was inadmissible and evidence insufficient to establish D involved in conspiracy to possess handgun; admissibility of opinions containing ultimate fact/issue.

Expert cannot establish loss of goodwill by focusing on increased expenses after condemnation and not comparing pre-taking and post-taking goodwill.

In medical negligence, D not entitled to SJ based on conclusory expert declaration stating opinion no malpractice occurred, but not explaining basis for opinion.

Prejudicial error to admit expert's testimony on "hedonic" damages for loss of enjoyment of life in auto PI case.

Expert opinion does not support use of marijuana-based drug for eye disease as a reasonable, current prescribing practice qualifying user for Medi-Cal benefits.

Expert testimony properly excluded where experts use improper method of valuation.

How the law should apply to particular facts is a legal question not susceptible to expert opinion.

Effect of expert's relying upon improper matter in forming opinion.