Under what circumstances can a witness's evidence be impeached?

A witness's evidence can be impeached when the witness has made inconsistent statements in the past. This is a critical aspect of witness credibility in legal proceedings. If a witness provides testimony that contradicts their prior statements, it raises questions about their reliability and truthfulness. Inconsistencies can occur in various forms, such as different accounts of an event or changes in details previously reported. Courts allow this type of impeachment because it directly affects how believable the witness's current testimony is, and it gives opposing parties the opportunity to challenge that credibility in front of the jury or judge.

In contrast, while a personal relationship with the defendant may introduce bias, it does not inherently provide grounds for impeaching the witness’s evidence unless it is shown to affect their reliability. Similarly, nervousness during testimony may be observed but does not constitute evidence of inconsistency or a lack of credibility on its own. Concerning minors, age can affect a witness's understanding and reliability but isn't a definitive factor for impeachment unless it is specifically relevant to their testimony. Thus, the most clear-cut situation for impeaching evidence relies on proving that the witness has previously made inconsistent statements.