What Is Rule 412? Rape Shield Exceptions and Procedures

Federal Rule of Evidence 412, often called the rape shield rule, bars evidence of an alleged victim’s sexual behavior or sexual predisposition in any civil or criminal proceeding involving sexual misconduct. Exclusion is the default. Evidence gets in only through a short list of exceptions in criminal cases, a demanding balancing test in civil cases, and a mandatory pretrial procedure that applies either way.¹

What the Rule Keeps Out

Two categories of evidence are presumptively inadmissible: evidence offered to prove that the victim engaged in other sexual behavior, and evidence offered to prove the victim’s sexual predisposition. The prohibition covers testimony about specific acts, opinion testimony, and reputation testimony alike.¹

Both categories reach further than the plain words suggest. The Advisory Committee Notes identify a victim’s mode of dress, speech, and lifestyle as examples of predisposition evidence that the rule excludes. So a defendant cannot introduce evidence that the victim wore particular clothing, went to bars alone, or kept an active dating life to invite the jury toward a consent inference. “Sexual behavior” has been read just as broadly, covering not only physical sexual contact but also use of contraceptives, evidence of sexually transmitted infections, and activities of the mind such as fantasies or dreams.¹

Exceptions in Criminal Cases

Criminal cases recognize three exceptions, and courts apply them strictly. Even when an exception technically fits, the trial judge still controls how much detail the jury actually hears.

Third-Party Source of Physical Evidence

A defendant may introduce evidence of specific instances of the victim’s sexual conduct with someone else, but only to prove that a person other than the defendant was the source of semen, injury, or other physical evidence.¹ This is a forensic exception. If DNA points somewhere else, the defense needs to be able to say so. It is not a doorway into the victim’s broader sexual history.

Prior Sexual Conduct With the Defendant

Evidence of specific instances of sexual behavior between the victim and the defendant is admissible when offered by the defense to prove consent, or when offered by the prosecution for its own purposes.¹ Prior consensual encounters between the same two people may bear on whether consent existed on the occasion charged. Prior encounters with anyone else do not, and remain excluded.

Constitutional Safety Valve

Evidence is admissible if excluding it would violate the defendant’s constitutional rights, including the Sixth Amendment right to confront witnesses and Fifth Amendment due process.¹ Most contested Rule 412 fights happen here, and the bar is high. The defense must show a direct, specific link between the evidence and a material issue. Generic arguments that the evidence “goes to credibility” rarely succeed.

Prior False Allegations

A common question sits just outside the rule. The Advisory Committee Notes say evidence of allegedly false prior claims by the victim is not barred by Rule 412 at all, because a false allegation is not “sexual behavior.”¹ That does not mean the evidence automatically comes in. It still must clear Rule 404’s limits on character and prior-act evidence and Rule 403’s balancing of probative value against unfair prejudice or confusion.² In practice, courts expect a solid factual basis showing the earlier claim was actually false, not just uncharged.

How Civil Cases Work

Civil cases use a different framework. Instead of enumerated exceptions, evidence of a victim’s sexual behavior or predisposition is admissible only if its probative value substantially outweighs both the danger of harm to the victim and the danger of unfair prejudice to any party.¹

This is the opposite of the usual presumption. Under Rule 403, evidence comes in unless the prejudice substantially outweighs the probative value.² Rule 412 flips the presumption: the evidence stays out unless probative value clears the higher bar, and the court must weigh potential psychological and emotional harm to the victim as part of the analysis. The burden falls on the party offering the evidence.

Reputation evidence gets its own sub-rule in civil cases. The court may admit evidence of the victim’s reputation only if the victim has placed it in controversy.¹ Filing a sexual harassment claim does not, by itself, put your sexual reputation in controversy. The victim must first introduce evidence about their own sexual conduct or reputation before the other side can respond in kind.

The Required Procedure

Even when an exception applies, the evidence does not simply walk into the courtroom. Rule 412 imposes a mandatory pretrial process, and skipping it results in exclusion regardless of relevance.

Motion and Notice

A party seeking to offer evidence under Rule 412(b) must file a written motion that specifically describes the evidence and the purpose for offering it. The motion must be filed at least 14 days before trial, though the court may set a different time for good cause, such as newly discovered evidence.¹ The moving party must serve all parties and separately notify the victim or, when appropriate, the victim’s guardian or representative, so the victim can be heard before anything reaches the jury.

In Camera Hearing and Sealing

Before admitting any evidence under the rule, the court must hold an in camera hearing, a closed proceeding outside the presence of the jury and the public. The victim and all parties have the right to attend and be heard.¹ Unless the court orders otherwise, the motion, related materials, and record of the hearing must be sealed and remain sealed. That default protects the information the rule is designed to shield even when the court ultimately rules the evidence inadmissible.

Consequences of Getting It Wrong

A Rule 412 error can support reversal on appeal. Trial-court rulings are generally reviewed for abuse of discretion, which gives the judge meaningful leeway, but applying the wrong legal framework is itself an abuse of discretion. When the claimed error involves a constitutional right, review is de novo, with no deference to the trial court.

For a defendant, the practical risk of ignoring the procedure is losing whatever argument the evidence supported. For a prosecutor who elicits protected testimony, the risk cuts the other way: a conviction obtained with improperly admitted sexual-history evidence is vulnerable to reversal and possible retrial.

State Rape Shield Laws

Rule 412 governs federal proceedings only. Forty-eight states and the District of Columbia have their own rape shield statutes, and they vary. Some mirror the federal structure closely, with enumerated exceptions and a constitutional catch-all. Others give judges broad case-by-case discretion without listing exceptions. A few key admissibility to the purpose of the offered evidence. If your case is in state court, the specific language of your state’s statute controls, and it may be more or less restrictive than the federal rule.

1
Legal Information Institute. Federal Rules of Evidence Rule 412 – Sex-Offense Cases: The Victim
2
Legal Information Institute. Federal Rules of Evidence Rule 403 – Excluding Relevant Evidence for Prejudice, Confusion, Waste of Time, or Other Reasons