[8] The prohibition against offering or using false evidence applies only if the lawyer knows that the evidence is false. A lawyer’s reasonable belief that evidence is false does not preclude its presentation to the trier of fact. A lawyer’s actual knowledge that evidence is false, however, can be inferred from the circumstances. See Rule 1.0(k) for the definition of “knowledge.” Thus, although a lawyer should resolve doubts about the veracity of testimony or other evidence in favor of the client, the lawyer cannot ignore an obvious falsehood.
[9] Although paragraph (a)(3) prohibits a lawyer from offering or using evidence the lawyer knows to be false, it permits the lawyer to refuse to offer testimony or other proof that the lawyer reasonably believes to be false. Offering such proof may impair the integrity of an adjudicatory proceeding. Because of the special protections historically provided criminal defendants, however, this Rule does not permit a lawyer to refuse to offer the testimony of a criminal defense client where the lawyer reasonably believes, but does not know, that the testimony will be false. Unless the lawyer knows the testimony will be false, the lawyer must honor the criminal defendant’s decision to testify.