CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Opinion & Scientific Evidence
......Content of Expert Opinion
.........Generally
 22 Cards On This Topic:
  • Expert may state reason and basis for opinion.
  • Expert need not testify in absolute terms or have firm opinion, so long as testimony helpful.
  • No error in excluding proffered expert evidence re D's defense of lingering doubt where D's conclusions speculative, inadmissible as evidence of 3d party culpability and irrelevant as to lingering doubt.
  • No error in admitting Deputy's expert testimony on D's gang affiliation and notes in his cell, offered only with respect to gang enhancement allegation, not to prove underlying charged offenses.
  • Harmless error to admit pathologist's testimony about the nonrobbery nature of most knife killings where D argued his mother and his child's mother were killed during robbery.
  • Although various expert Ws for defense and DA each used slightly different terminology, the testimony of the two DA expert witnesses was proper rebuttal, and trial court, in allowing testimony, did not commit "palpable error."
  • DA expert’s testimony should be directed to the expert testimony given in case, and objections sustained when E gives general opinion concerning psychological evidence not specifically related to case.
  • Court did not err in permitting victim's doctor to review and elaborate on some of same ground covered in V's unobjectionable testimony.
  • No error in allowing radiologist to perform X-ray size comparison by X-raying bullet in victim next to bullets taped to his stomach; Kelly inapplicable as it was not an experiment.
  • Rebuttal E's testimony re unreliability of psych testimony was neither improper nor prejudicial; criticism of forensic psych and defense experts went to weight of opinions not admissibility.
  • Expert testimony on use of excessive force assisted jury as it provided relevant context and a basis for evaluating Os' handling techniques and decision to use assistive tools such as Taser and handcuffs
  • Gang findings reversed as E's predicate offenses were committed by Norteño subset members different than Ds' subsets and no substantial evidence linked them to each other or to the greater Norteño gang Ds were supposed to be benefitting.
  • Evidence sufficient to support gang enhancements where experienced, credible expert's "conclusions were [not] spun out of whole cloth" nor based on speculation.
  • No error in allowing Homeland Security Agent to testify D was not a "blind mule" unknowingly bringing drugs in from MX where Agent relied on specific factors and evidence in reaching that conclusion.
  • Given the lack of substantial evidentiary support for gang expert's opinion that D's criminal threats and false imprisonment were gang-related and for the gang's benefit, true findings on the gang allegations had to be stricken.
  • Expert gang testimony, along with other evidence, provided the connection required by Prunty linking Ds and subsets to a larger criminal street gang.
  • E's testimony interpreting Ds' past phone calls as concerning planned action against rival gang was not inadmissible opinion about D1's subjective knowledge and intent.
  • Expert may be precluded from expressing opinions not testified to at deposition.
  • To extent E's opinion re V's mental competence was based on videotaped interviews with V, confrontation clause did not prevent E from rendering her opinion and stating the sources she relied on in reaching it.
  • No abuse of discretion in admitting E's videotape presented for the simple point that a paper towel does not necessarily extinguish in midair when thrown.
  • P's tire expert's testimony properly excluded, and her directional stability expert's properly limited, where there was no foundation for their opinions or conclusions.
  • As doctor provided no testimony of V's character for untruthfulness, no error in omitting character instruction re credibility.


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