Though partisan hot takes would suggest otherwise, the Supreme Court nomination process is not a courtroom trial. In Brett Kavanaugh's case, however, as legal experts debate the necessity of an FBI investigation and the burden of proof to be applied to the accusations of Christine Blasey Ford, Deborah Ramirez, and Julie Swetnick, lessons from a “real” trial can help sort through the misinformation and assess the serious allegations against him.

First, the touchstone of the rules of evidence is reliability in the quest for truth. Sexual assaults are known to be underreported to police, and even to friends and family. This concern is compounded in a case that will receive intense public scrutiny. In court, statements made against a person's own interests—like the interest in retaining one's privacy or one's immunity from anonymous threats—are regarded as reliable.

That is why the law only permits hearsay to be used as evidence if the person quoted has made a statement that might harm himself. Simply put, people generally do not make statements against their own interests unless their interest in telling the truth outweighs the potential losses. The evidence rules applicable in court aren't applicable in confirmation hearings, and, since Dr. Blasey will tell her own story, hearsay is not an issue. But the underlying principle that a person speaking against her own interests can be believed is fully implicated in this case, and it points strongly in favor of believing Dr. Blasey.

Second, concerning Ms. Ramirez, defenders of Judge Kavanaugh have made much of the fact that she was reluctant to name him in her initial conversations with reporters from the New Yorker. They have also asked why she would speak with her lawyer, as opposed to a psychologist, in order to test her memory. From a legal point of view, however, this is exactly what she should have done. Anyone publicly accusing another person of a sexual assault runs the risk of being sued for defamation. It makes perfect sense to talk to a lawyer before making a definitive statement to a reporter, and specifically to have that lawyer test the quality of one's memory.

A special rule applies in defamation cases involving public figures: an accuser is not liable for defamation unless she acts with reckless disregard for the truth. This rule makes it more difficult to prove a person liable for the defamation of a prominent person, so it protects someone such as Ms. Ramirez. Whether or not the accuser acted with reckless disregard is generally a difficult call for a judge or jury to make—but consulting with a lawyer before speaking up is definitive proof that the accuser was not reckless at all. It shows instead that she was careful about telling the truth.

Third, given Republican senators' confidence that Dr. Blasey and Ms. Ramirez are not telling the truth, they have every reason to ask the FBI to investigate the accusations. An investigation would definitively establish what they purport to believe, and cross-examining the accusers could poke holes in their allegations and cast doubt on their credibility.

The reason they have not and will not request an official investigation, however, is obvious to any trial lawyer. It is a cardinal rule of cross-examination that you never ask a question that you don't know the answer to. An FBI investigation might cast doubt on the allegations against Judge Kavanaugh, but there is no way to rule out the possibility that it would support the allegations or even produce new ones. The Republican senators' refusal to call in the FBI makes perfect sense given how strongly these hearings have come to resemble a trial. But the truth is obscured when relevant questions aren't asked on cross-examination, and the same is true in the case of Judge Kavanaugh.

It bears repeating that Judge Kavanaugh's confirmation hearings—which now include a hearing on Dr. Blasey's allegation—are fundamentally different from a courtroom trial. Nor should they be treated as the equivalent of one. Nevertheless, a fundamental principle of evidence law, the standard governing a defamation case, and the primary rule of cross-examination tell us, at the very least, that the allegations against Judge Kavanaugh cannot be dismissed out of hand.

Kyron Huigens is a professor of law at Yeshiva University's Benjamin N. Cardozo School of Law.