For what reasons are past instances of a victim's sexual behavior admissible in court?

The admissibility of past instances of a victim's sexual behavior in court primarily hinges on the principle that such evidence will be considered if its probative value outweighs its prejudicial effect. This standard is rooted in the desire to ensure that the evidence presented contributes meaningfully to the case without unfairly biasing the jury against the victim.

In many jurisdictions, rules governing evidence concerning a victim's sexual history are carefully controlled due to concerns about potential stigma and victim-blaming that such evidence can evoke. Therefore, if a court finds that the evidence in question has significant relevance to a material fact in the case—such as issues of consent or credibility—it may allow it under the condition that its introduction does not cause undue harm or prejudice against the victim.

This framework is important to protect victims from being judged by their past sexual behavior rather than focusing on the actual events surrounding the current case. It is the balance of these two competing interests—truth-seeking and protection from prejudice—that allows for the introduction of this evidence under strict conditions.