A witness (including a party) may be impeached (meaning that the witness's testimony is discredited) by contradictory evidence you find to be true [or by evidence that on a former occasion the witness made a statement or acted in a manner inconsistent with the present testimony,] [or by evidence of conviction of a crime,] [or by evidence of character for untruthfulness].
If you conclude that a witness has been impeached, you may give the testimony of that witness such weight and credibility, if any, as you think it deserves.
[If you conclude that a witness has been impeached by an earlier contradictory statement, the statement may be considered by you as evidence only if the statement was given under oath, in which event you may determine which is the truth - the present testimony or the earlier statement.]
If you conclude that a witness has willfully, knowingly, or intentionally testified falsely concerning a material fact in this case, you may wholly disregard the witness's testimony unless it is corroborated by other credible evidence.
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