Cal. Rules of Prof. Conduct, rule 3.4 · Chapter 3. Advocate
Fairness to Opposing Party and Counsel
Text — 2026 edition, as the State Bar of California publishes it (read October 22, 2026)
A lawyer shall not:
(a) unlawfully obstruct another party’s access to evidence, including a witness, or unlawfully alter, destroy or conceal a document or other material having potential evidentiary value. A lawyer shall not counsel or assist another person* to do any such act;
(b) suppress any evidence that the lawyer or the lawyer’s client has a legal obligation to reveal or to produce;
(c) falsify evidence, counsel or assist a witness to testify falsely, or offer an inducement to a witness that is prohibited by law;
(d) directly or indirectly pay, offer to pay, or acquiesce in the payment of compensation to a witness contingent upon the content of the witness’s testimony or the outcome of the case. Except where prohibited by law, a lawyer may advance, guarantee, or acquiesce in the payment of:
(1) expenses reasonably* incurred by a witness in attending or testifying;
(2) reasonable* compensation to a witness for loss of time in attending or testifying; or
(3) a reasonable* fee for the professional services of an expert witness;
(e) advise or directly or indirectly cause a person* to secrete himself or herself or to leave the jurisdiction of a tribunal* for the purpose of making that person* unavailable as a witness therein;
(f) knowingly* disobey an obligation under the rules of a tribunal* except for an open refusal based on an assertion that no valid obligation exists; or
(g) in trial, assert personal knowledge of facts in issue except when testifying as a witness, or state a personal opinion as to the guilt or innocence of an accused.
Notes and commentary — not rule text
Comment
[1] Paragraph (a) applies to evidentiary material generally, including computerized information. It is a criminal offense to destroy material for purpose of impairing its availability in a pending proceeding or one whose commencement can be foreseen. (See, e.g., Pen. Code, § 135; 18 U.S.C. §§ 1501-1520.) Falsifying evidence is also generally a criminal offense. (See, e.g., Pen. Code, § 132; 18 U.S.C. § 1519.) Applicable law may permit a lawyer to take temporary possession of physical evidence of client crimes for the purpose of conducting a limited examination that will not alter or destroy material characteristics of the evidence. Applicable law may require a lawyer to turn evidence over to the police or other prosecuting authorities, depending on the circumstances. (See People v. Lee (1970) 3 Cal.App.3d 514, 526 [83 Cal.Rptr. 715]; People v. Meredith (1981) 29 Cal.3d 682 [175 Cal.Rptr. 612].)
[2] A violation of a civil or criminal discovery rule or statute does not by itself establish a violation of this rule. See rule 3.8 for special disclosure responsibilities of a prosecutor.
Source of truth
- Edition
- 2026 edition, as the State Bar of California publishes it (read October 22, 2026)
- Official file
- https://www.calbar.ca.gov/sites/default/files/portals/0/documents/rules/Rules-of-Professional-Conduct.pdf (PDF pages 46–47)
- Text hash
- sha256 d2604246b315d112e1eb7a7f280ba16761b647996a79b70786fabe3fcd483920
- Composed by
- rpc/build 2026-10-22: the State Bar's 2026 PDF (pages 12-71) read by two readers, PyMuPDF glyph positions and pdfminer with the PDF's tagged structure, agreeing on 834 of 843 paragraphs character for character, the other nine (paragraph boundaries only) resolved against the rendered page; 205,485 printed glyphs accounted for; the State Bar's chapter pages a third reading
This rule cites
Provisions in this library that the text above cites, as it prints each citation. A range cited as “ss. 61.13-61.16” links its first and last provisions.
California Rules of Professional Conduct
Cited by 2 provisions
Provisions in this library whose text cites Cal. Rules of Prof. Conduct, rule 3.4. Each shows the citation as that text prints it.
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.