Expert Witnesses Generally - Expert Witnesses - Evidence - CA

Section § 720

This section explains when a person can be considered an expert witness in a court case. To testify as an expert, a person must have specialized knowledge, skills, experience, training, or education related to their testimony's topic. If someone challenges the expert's qualifications, these qualities must be demonstrated before they can testify. Additionally, a person's expertise can be proved using any acceptable evidence, including their own statements.

(a) A person is qualified to testify as an expert if he has special knowledge, skill, experience, training, or education sufficient to qualify him as an expert on the subject to which his testimony relates. Against the objection of a party, such special knowledge, skill, experience, training, or education must be shown before the witness may testify as an expert.

(b) A witness’ special knowledge, skill, experience, training, or education may be shown by any otherwise admissible evidence, including his own testimony.

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Section § 721

This law explains that an expert witness, like any other witness, can be questioned thoroughly about their qualifications, the topic they're testifying about, and the basis for their opinion. However, if the expert gives an opinion based on scientific or professional publications, they can't be asked about the content of these publications unless they have used them to form their opinion, the publication is already in evidence, or it's recognized as reliable by experts or the court. If such a publication is used, you can read relevant parts aloud in court, but it can't be entered as an exhibit.

(a) Subject to subdivision (b), a witness testifying as an expert may be cross-examined to the same extent as any other witness and, in addition, may be fully cross-examined as to (1) his or her qualifications, (2) the subject to which his or her expert testimony relates, and (3) the matter upon which his or her opinion is based and the reasons for his or her opinion.

(b) If a witness testifying as an expert testifies in the form of an opinion, he or she may not be cross-examined in regard to the content or tenor of any scientific, technical, or professional text, treatise, journal, or similar publication unless any of the following occurs:

(1) The witness referred to, considered, or relied upon such publication in arriving at or forming his or her opinion.

(2) The publication has been admitted in evidence.

(3) The publication has been established as a reliable authority by the testimony or admission of the witness or by other expert testimony or by judicial notice.

If admitted, relevant portions of the publication may be read into evidence but may not be received as exhibits.

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Section § 722

This law allows the court to inform the jury or judge deciding a case that an expert witness has been appointed. Additionally, any opposing party can question how much the expert is being paid by the party who called them, as this information can affect how credible or reliable the expert's testimony is considered.

(a) The fact of the appointment of an expert witness by the court may be revealed to the trier of fact.

(b) The compensation and expenses paid or to be paid to an expert witness by the party calling him is a proper subject of inquiry by any adverse party as relevant to the credibility of the witness and the weight of his testimony.

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Section § 723

This law allows a court to decide how many expert witnesses each party can bring in a trial. The court can make this decision at any time before or during the trial.

The court may, at any time before or during the trial of an action, limit the number of expert witnesses to be called by any party.

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