Witness Impeachment - Parties Who May Impeach

Parties Who May Impeach

Under the common law of England, a party could not impeach its own witness unless one of four special circumstances was met. This was due to the Voucher Rule, which required that the proponent of the witness "vouch" for the truthfulness of the witness. Here are the special circumstances:

1. If the witness was an adverse party (example: if the plaintiff called the defendant to the stand, or vice-versa).
2. If the witness was hostile (example: the witness refused to cooperate).
3. If the witness was one that the party was required by law to call as a witness.
4. If the witness surprised the party who called him by giving damaging testimony against that party.

This rule has been eliminated in many jurisdictions. Under the United States Federal Rules of Evidence, Rule 607 permits any party to attack the credibility of any witness.