(b) SPECIFIC INSTANCES OF CONDUCT. Except for a criminal conviction under Rule 609, extrinsic evidence is not admissible to prove specific instances of a witness’s conduct in order to attack or support the witness’s character for truthfulness. But the court may, on cross-examination, allow them to be inquired into if they are probative of the character for truthfulness or untruthfulness of:
(2) another witness whose character the witness being cross-examined has testified about.
US Supreme Court // ©
(As amended Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 25, 1988, eff. Nov. 1, 1988; Mar. 27, 2003, eff. Dec. 1, 2003; Apr. 26, 2011, eff. Dec. 1, 2011.)


