Advocate-Witness Rule Law and Legal Definition

Advocate witness rule is a principle prohibiting an attorney from serving as an advocate and a witness in the same case. However, advocates are allowed to serve as witnesses if their testimony is about factual matters that have no bearing on the case; likewise, they are allowed to remain as counsel if their removal from the case would create a substantial hardship for the client. The rule does not prohibit attorneys from being witnesses in general, nor does it prohibit an attorney-witness from assisting in a client's case. The rule permits an attorney actively participating in the case to be a witness on merely formal matters but discourages testimony on other matters on behalf of a client. American Bar Association’s Model Rule of Professional Conduct 3.7 (1983) speaks about this rule. It reads as follows:

Rule 3.7 Lawyer As Witness

(a) A lawyer shall not act as advocate at a trial in which the lawyer is likely to be a necessary witness unless:

(1) the testimony relates to an uncontested issue;

(2) the testimony relates to the nature and value of legal services rendered in the case; or

(3) disqualification of the lawyer would work substantial hardship on the client.

(b) A lawyer may act as advocate in a trial in which another lawyer in the lawyer's firm is likely to be called as a witness unless precluded from doing so by Rule 1.7 or Rule 1.9.

Advocate-witness rule is also known as lawyer-witness rule or attorney-witness rule.