Legal Definitions - impeachment of a witness

Impeachment of a witness is when a lawyer tries to show that a witness is not telling the truth or is not reliable. This is done by presenting evidence or asking questions that contradict what the witness said or show that the witness has a bias or has lied before.

For example, if a witness says they saw a car accident happen at 3:00 PM, but another witness says they saw the same accident happen at 2:30 PM, the first witness's credibility may be impeached. Another example is if a witness has a criminal record, a lawyer may use that information to show that the witness is not trustworthy.

Impeachment of a witness is a common strategy used by lawyers to challenge the truthfulness of a witness's testimony. It is important because the credibility of a witness can greatly affect the outcome of a trial.