At a criminal trial, the prosecutor is likely to have a list of witnesses to put on the stand in order to provide testimony against the defendant. Witness testimony can be powerful and help the prosecutor meet the burden of proving a defendant guilty beyond a reasonable doubt. Fortunately, however, there are several ways of negating or at least reducing the impact witness testimony can have on a judge or jury. One such way is by impairing, or “impeaching,” the credibility of a witness. You see, the defendant has a constitutionally protected right to challenge witnesses for the prosecution. The defense attorney has the right to cross-examine every witness the prosecution presents. The defense attorney can impeach a witness’s credibility in order to show that the witness is unreliable or untrustworthy.
Impairing the Credibility of a Witness
When a witness is impeached, and credibility is called into question, the force of the witness’s testimony can be eliminated or, at the very least, significantly reduced. The credibility of a witness can be impaired due to a number of reasons. It could be shown that the witness is potentially lying on the stand, which would mean that the witness was committing the offense of perjury. Alternatively, it could be suggested that, while the witness may try to tell the truth, the witness is not recalling facts accurately. It could also be possible that the witness is being selective in the testimony being provided, omitting certain details while emphasizing others, for example.
In order to impair the credibility of a witness, it is unlikely that a defense attorney will ask the witness directly if the testimony is dishonest or inaccurate. Alternatively, a defense attorney is likely to employ a number of strategies to have such things revealed in other ways, such as calling a witness’s character into question or otherwise challenging the accuracy of the testimony being presented.
One commonly employed tactic for undermining the credibility of a witness is for the defense to present evidence of bias. When bias or even potential bias on the part of a witness is introduced, the witness’s capacity for telling the truth is called into question. Bias can be shown in a number of ways, including presenting evidence of a witness’s relationship to a party involved in the case. When a witness’s personal feelings towards a person are considered, the testimony relating to that individual can be undermined.
The credibility of a witness may also be questioned if it can be shown that the witness has ulterior motives for the testimony provided. A witness, for instance, may have a personal interest in the outcome of the case and may even be under threat of being criminally charged as well. The defense team has the right to question a witness about any criminal charges that may have recently been dismissed or if there is an agreement in place between the witness and the prosecution.