CALCRIM No. 332. Expert Witness Testimony
Judicial Council of California Criminal Jury Instructions (2023 edition)Download PDF
332.Expert Witness Testimony
(A witness was/Witnesses were) allowed to testify as [an] expert[s] and to
give [an] opinion[s]. You must consider the opinion[s], but you are not
required to accept (it/them) as true or correct. The meaning and
importance of any opinion are for you to decide. In evaluating the
believability of an expert witness, follow the instructions about the
believability of witnesses generally. In addition, consider the expert’s
knowledge, skill, experience, training, and education, the reasons the
expert gave for any opinion, and the facts or information on which the
expert relied in reaching that opinion. You must decide whether
information on which the expert relied was true and accurate.
You may disregard any opinion that you find unbelievable, unreasonable,
or unsupported by the evidence.
[An expert witness may be asked a hypothetical question. A hypothetical
question asks the witness to assume certain facts are true and to give an
opinion based on the assumed facts. It is up to you to decide whether an
assumed fact has been proved. If you conclude that an assumed fact is
not true, consider the effect of the expert’s reliance on that fact in
evaluating the expert’s opinion.]
[If the expert witnesses disagreed with one another, you should weigh
each opinion against the others. You should examine the reasons given
for each opinion and the facts or other matters on which each witness
relied. You may also compare the experts’ qualifications.]
New January 2006; Revised March 2018
When expert testimony is received at trial, the court must sua sponte instruct the
jury on evaluating the expert’s testimony. (Pen. Code, § 1127b.)
Give the bracketed paragraph beginning, “An expert witness may be asked a
hypothetical question,” if an expert witness responded to a hypothetical question.
Give the bracketed paragraph beginning, “If the expert witnesses disagreed with one
another,” if there is conflicting expert testimony.
• Instructional Requirements. Pen. Code, § 1127b.
• Inadmissible Case-Specific Hearsay Not Basis for Expert Testimony. People v.
Sanchez (2016) 63 Cal.4th 665, 684-686 [204 Cal.Rptr.3d 102, 374 P.3d 320];
People v. Vega-Robles (2017) 9 Cal. App. 5th 382, 416 [215 Cal.Rptr 3d 284].
4 Witkin & Epstein, California Criminal Law (4th ed. 2012) Criminal Trial, § 725.
1 Witkin, California Evidence (5th ed. 2012) Opinion Evidence, § 86.
3 Millman, Sevilla & Tarlow, California Criminal Defense Practice, Ch. 71,
Scientific and Expert Evidence, § 71.04 (Matthew Bender).
4 Millman, Sevilla & Tarlow, California Criminal Defense Practice, Ch. 85,
Submission to Jury and Verdict, §§ 85.02[a][ii], 85.03[b], Ch. 86, Insanity
Trial, § 86.04[a] (Matthew Bender).
EVIDENCE CALCRIM No. 332