Also known as: impeach a witness · impeaching a witness · impeached witness · witness impeachment · witness credibility · impeach witness
Written by attorneys · grounded in primary & secondary sources — see below
A method of challenging a witness's credibility by introducing evidence or questions that cast doubt on the witness's truthfulness, perception, memory, bias, or character for honesty.
Israel Irving testified that containers were properly sealed before loading. On cross-examination, opposing counsel asked about his membership in the Seafarers' Divine Fellowship, whose tenets require loyalty to ship captains and favorable testimony for the company. The inquiry was permitted to show bias.
Igor Ito testified he saw the defendant walking normally in the lockup. Defense counsel impeached him by establishing that the observation occurred outside his official duties and was unrelated to his position, undermining the reliability of his account.
Select any source to read its text and confirm it supports the definition.
Isabella Ingram testified for the prosecution about cargo handling. Defense counsel sought to impeach her by questioning her about a probationary cooperation agreement that could lead to early termination of supervision if she assisted federal agents.
Imani Idowu testified about events in a conspiracy prosecution. The defense impeached her by exploring whether her testimony was influenced by a desire to curry favor with prosecutors in exchange for leniency on her own charges.
Isla Ireland testified about a prior investigation. Counsel attempted to impeach her using notes prepared by an attorney summarizing witness interviews, but the court protected the materials as opinion work product.
Ivy Ibarra identified the defendant at trial. Defense counsel impeached the identification by showing that the witness had been exposed to suggestive circumstances that could have corrupted the reliability of her memory.
Impeachment may target bias, prior inconsistent statements, character for truthfulness, capacity to perceive or remember, or specific instances of conduct. Bias evidence is always admissible and relevant.
Supporting sources
Evidence of religious beliefs is generally inadmissible to attack credibility under Rule 610, but organizational membership that creates bias may be explored even if framed in religious terms when the focus remains on the incentive to lie rather than the belief itself.
Supporting sources
Juvenile adjudications are generally inadmissible for impeachment in civil cases. In criminal cases the Confrontation Clause may require admission when the evidence is necessary to show bias and the witness's credibility is central to guilt or innocence.
Supporting sources
…of the other testimony. In this instance, the State argued that Carter's testimony was an impermissible attempt by petitioner to impeach a witness (McDonald) who was not adverse to him. The trial court did not state why it was excluding the evidence but the State Supreme Court indicated that it was excluded as hearsay. 252 So. 2d, at…