Pen. Code, § 1127b · Chapter 2. The Trial
Pen. Code, § 1127b
Text — As published in the Legislative Counsel's database, tables dated October 18, 2026 (pubinfo_2025.zip)
When, in any criminal trial or proceeding, the opinion of any expert witness is received in evidence, the court shall instruct the jury substantially as follows:
Duly qualified experts may give their opinions on questions in controversy at a trial. To assist the jury in deciding such questions, the jury may consider the opinion with the reasons stated therefor, if any, by the expert who gives the opinion. The jury is not bound to accept the opinion of any expert as conclusive, but should give to it the weight to which they shall find it to be entitled. The jury may, however, disregard any such opinion, if it shall be found by them to be unreasonable.
No further instruction on the subject of opinion evidence need be given.
Notes and commentary — not statutory text
History
Added by Stats. 1929, Ch. 876.
Source of truth
- Edition
- As published in the Legislative Counsel's database, tables dated October 18, 2026 (pubinfo_2025.zip)
- Official file
- https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=1127b.
- Text hash
- sha256 43eb98ef5ac146809e5c8cd0374cde63b3eae169d4e9f062da3932fd5ec3c147
- Composed by
- compose_ca.py 2026-10-22: the Legislative Counsel's CAML content files read by a tokenizer (caml_readers.reader_a); an independent xml.etree reading (caml_readers.reader_b) agrees on every section
Procedural information only. Not legal advice and not a substitute for the advice of an attorney. Confirm the current text with the official publisher before relying on it.