I devote a lot of class time to discussion of the law governing rape and sexual assault in my evidence course. The controversy surrounding the allegation that Vice President Biden committed a sexual assault against a staff member when he was a Senator twenty-seven years ago provides a good occasion to review that body of law and to try to use it as a basis for evaluating charges of this type.

Any discussion of this topic should begin with recognition that our legal system has never done a good job of evaluating claims of rape and sexual assault. We have made important improvements in recent years as a result of the enactment of rape shield laws that limit the use of an alleged victim’s sexual history during a trial, greater appreciation of the probative value of evidence of modus operandi (m.o.), and greater willingness of the public to take allegations of rape and sexual assault seriously. Even with those improvements, however, rape and sexual assault are crimes that are massively underreported and under prosecuted. Cases of rape and sexual assault are notoriously difficult to resolve for two main reasons.

First, they often arise in circumstances in which only two people know what happened. The alleged victim often claims that the accused did something in a private setting that the accused says he did not do. When both parties agree on the conduct that took place, they almost invariably disagree about whether the conduct was consensual. In most cases, only the alleged victim and the accused have direct knowledge of the conduct and whether the alleged victim consented to the conduct. No legal system is capable of making a confident decision about who is telling the truth in that typical situation. Since the alleged victim has the burden of proof in a civil case and the prosecutor has a particularly heavy burden of proof in a criminal case, juries often make erroneous findings in favor of the defendant in cases in which the alleged victim actually was raped or sexually assaulted.    

Second, even with the limits on the use of an alleged victim’s sexual history created by rape shield laws, any victim of rape or sexual assault must pay a high price for making a public charge of rape or sexual assault. The victim must relive the events in preparation to testify and then again at trial. That experience is extraordinarily painful and embarrassing. Given the difficulty of proving that the rape or sexual assault actually occurred, that painful and embarrassing experience often yields only a frustrating jury verdict of acquittal that causes the victim even more pain and embarrassment.

When a prosecutor decides to charge someone with rape or sexual assault all of the safeguards of our criminal justice system apply. The jury is instructed that the defendant is entitled to a presumption of innocence and that the jury can convict the defendant only if it finds that he is guilty beyond a reasonable doubt. In the context of a typical rape or sexual assault case, in which there are only two witnesses who know what happened and they provide conflicting testimony, it is highly unlikely that the jury will find the defendant guilty even if he committed the crime. 

It follows logically that prosecutors often refuse to charge a defendant with rape or sexual assault even when the prosecutor is confident that the defendant committed the crime. Moreover, victims of rape or sexual assault are unwilling to endure the extreme pain and embarrassment of reporting a rape or sexual assault and offering to testify against the perpetrator of the crime when the most likely result is the additional pain and embarrassment created by a jury verdict of acquittal.

In recent years, prosecutors have discovered a means through which they can often successfully prosecute someone for rape or sexual assault. It is rare for a man to respect the autonomy of women in most circumstances and then to depart completely from that behavioral norm by raping or sexually assaulting a woman on a particular occasion. The vast majority of rapes and sexual assaults are committed by men who have never internalized the value of a woman’s autonomy. They frequently act in ways that reflect that flaw in their character. Moreover, they typically follow the same pattern of behavior when they engage in rape or sexual assault.

This discovery fits well with the rules of evidence. While evidence of a criminal defendant’s character is not admissible to prove that the defendant acted in a manner that is consistent with his character, it is admissible to prove that the defendant acted in a way that is consistent with his distinctive m.o. Men who commit rape and sexual assault usually do so in a particular manner that qualifies their conduct on prior occasions as evidence of a distinctive m.o.

The case of Bill Cosby is one of many recent cases that illustrates the increasing importance of evidence of distinctive m.o. When a woman accused Cosby of rape and a prosecutor attempted to convict Cosby of that rape, the prosecution predictably failed. The public revelation of that accusation of rape had the effect of inducing many women who had been similarly victimized to make similar claims, however. Each woman had been reluctant to publicize her allegation for good reasons when she thought that she would be the only person who made such an allegation. The likelihood of a successful prosecution was so poor that the woman decided that she should not endure the pain and embarrassment that is inevitable when a woman accuses a man of rape or sexual assault when the result was likely to be an acquittal that would just add to the pain and embarrassment of making the accusation public. 

Once each of the victims learned that she was not alone, the likelihood of a successful prosecution of Cosby increased significantly. The pain and embarrassment each victim would suffer as a result of public disclosure of the crime diminished as each victim realized that the public attention would focus primarily on the man who committed the crimes, with little risk that the jury or the public would find the man’s story plausible. In the second case in which a prosecutor brought an action against Cosby for rape, the jury found Cosby guilty. In that case, other past victims were allowed to testify to the distinctive m.o. that Cosby used. In each case he gave the victim a drink in which he had surreptitiously placed a drug that caused the victim to lose control of her mind and body to such an extent that Cosby could rape her.

Prosecutors across the country have learned important lessons from the Cosby case. When a woman makes a credible report of rape or sexual assault, the prosecutor tries to persuade the victim to make her complaint public or to allow the prosecutor to do so to induce other victims of sexual misconduct committed by the same man to come forward. If the victim refuses to do so, the prosecutor files the report and begins to look for other reports involving the same man and the same m.o. When the prosecutor identifies two or more women who have made similar reports of sexual misconduct the prosecutor returns to the first victim and renews the effort to persuade her to testify. As the number of victims who have made similar reports increases, the prosecutor’s task of persuading each victim to make her accusation public and to testify against the defendant increases. 

The prosecutor’s likelihood of success increases significantly as a result of the availability of testimony from multiple victims through use of the distinctive m.o. basis for admission of testimony. It is much easier to overcome the presumption of innocence and to satisfy the beyond a reasonable doubt burden of proof when three or more witnesses describe a similar pattern of criminal behavior than when the jury is asked to decide that the testimony of a single witness is so compelling that it can be the basis for a verdict of guilt when it is contradicted by the testimony of the only other witness.

The legal framework applicable to civil actions differs significantly from the framework applicable to criminal actions. If an alleged victim of rape or sexual assault files a civil action for damages or a state university attempts to discipline a student for rape or sexual assault, the defendant does not have the benefit of a presumption of innocence, and the plaintiff must only prove the elements of the offense by a preponderance of the evidence. That reduces the obstacles to a successful outcome for the plaintiff but the victim still must endure the pain and embarrassment of reliving the events at a trial or hearing subject to predictably vigorous cross-examination by the lawyer for the defendant. Many universities attempted  to deprive students who were accused of sexual misconduct of their right to cross-examine the alleged victim, but courts have consistently held that a student who faces the risk of expulsion or suspension based on a finding that the student engaged in rape or sexual assault must be given the opportunity to cross-examine the witnesses against him.

The cases that have produced a lot of public controversy recently involve allegations that candidates for  appointment, e.g., Justice Kavanaugh,  or candidates for elected office, e.g. Vice President Biden , engaged in sexual assault. Neither of these contexts involve decisions of judges or juries. None of the legal doctrines that apply to judges and juries have any application in these contexts. Thus, the accused is not entitled to a presumption of innocence and the complaining party is not required to prove the elements of the offense either beyond a reasonable doubt or by a preponderance of the evidence.

The decision whether to confirm a nominee to be a Judge, Justice or Officer of the United States is committed to the discretion of the Senate. The decision whether to elect a candidate for President, Vice President, or member of Congress is committed to the discretion of the electorate. There are no legal rules that limit the discretion of either the Senate or the electorate, but the legal framework that applies to charges of rape and sexual assault and our experience in applying those rules can help members of the Senate and voters decide how to evaluate charges of rape or sexual assault.

The starting point in evaluating a claim that a candidate for office engaged in sexual misconduct is easy to identify. Any allegation of rape or sexual assault should be taken seriously and should be investigated thoroughly. Even complaints of misconduct that allegedly took place decades ago should be taken seriously. We know that victims are frequently unwilling to make a public complaint at or near the time that the conduct occurred because of the pain and embarrassment that any such complaint will cause the victim and the low probability that the complaint will be the basis for a successful prosecution.

A long gap between the time of the occurrence of the conduct and the complaint should not reduce the significance we attach to the complaint. However, passage of time between the alleged conduct and the complaint necessarily will limit significantly the nature and quality of the investigation of the claim that anyone can conduct. Passage of a long period of time between the alleged misconduct and the investigation reduces our ability to undertake a thorough investigation. Memories fade and evidence disappears over time.

In a criminal case, the investigation is done by the police, but the police rarely can investigate old allegations of wrongdoing by candidates for office. In both the Kavanaugh case and the Biden case, the statute of limitations had expired long ago and there was no chance that any investigation would produce evidence sufficient to support a criminal charge. 

Both Kavanaugh and Biden had previously held high offices so both had been the subject of prior FBI investigations. The background investigations the FBI conducts bear no relationship to a criminal investigation, however. They are unlikely either to disclose an allegation of sexual misconduct that was not previously made public or to shed much light on the circumstances surrounding an allegation that someone engaged in sexual misconduct decades ago.

In the case of Kavanaugh, or any other nominee for a position as a Judge, a Justice, or an Officer of the United States, a Senate Committee conducts a background investigation followed by a confirmation hearing. Those investigations and hearings may further important political goals and they often are platforms for entertaining theatrical performances, but they have little chance of producing the kind of evidence that is useful in the process of evaluating a claim of sexual misconduct.

The most promising source of a thorough investigation of alleged sexual misconduct by a candidate for office is the press. Investigative reporters lack some of the valuable tools of investigation, like the power to subpoena witnesses and to conduct searches. However, they have proven to be extraordinarily effective in the process of investigating allegations of sexual misconduct by powerful people. The Jeffrey Epstein case provides a recent illustration of the ability of the press to uncover facts that eluded police, prosecutors and the public for decades.

The press faces enormous obstacles in any attempt to investigate old previously undisclosed complaints of sexual misconduct, however. There are often only two witnesses to the conduct at issue. That is the situation with respect to Ms. Reade’s allegation against Vice President Biden. Dr. Ford alleged that there were witnesses to Justice Kavanaugh’s misconduct, but she could recall the identity of only one—a person who had since written a book in which he described the serious problems of alcoholism and abuse of other substances that caused him to have no reliable memory of any events that occurred during the relevant time period.

In neither case was the alleged victim able to provide evidence to corroborate her claim. Each said that she had confided with others over the decades since the relevant conduct occurred, but efforts by reporters to confirm those claims produced at best mixed results. A few claimed to remember a conversation of the type described by the alleged victim but many had no recollection of any such conversation. Neither of the alleged victims could recall any of the details surrounding the conduct that might provide a path to evidence that would corroborate or refute the claims. Neither could describe the location, date or time at which the conduct took place. No investigation is likely to yield much useful evidence in these circumstances.

Both Senators and voters  appropriately consider the pre-existing reputation of candidates for office who are accused of sexual misconduct.  Both Biden and Kavanaugh enjoyed excellent reputations prior to the public revelation of the charges of sexual misconduct. There are two important limits to the value of reputation for this purpose, however. 

First, the reputation of a major public figure usually varies among communities. It is regrettable but inevitable that a disproportionate number of Republicans believe Kavanaugh and Reade, while a disproportionate number of Democrats believe Biden and Ford. Second, because of the understandable reluctance of victims of sexual misconduct by famous people to make their claims of misconduct public in a timely manner, an excellent reputation can be based on inadequate information. I must confess that I was one of the millions of people who held Bill Cosby in high regard before scores of women told nearly identical stories about the way that he drugged and raped them.

The Cosby case also illustrates the most important factor that can help a member of the Senate or a voter evaluate a claim of sexual misconduct. We now know that most acts of sexual misconduct are committed by serial predators. We also know that victims of sexual misconduct committed by famous people typically break their silence once one or two victims are brave enough to describe the behavior of the sexual predator. If a woman makes public a claim that a famous person raped or sexually assaulted her, the most powerful evidence of guilt will come in the form of allegations by many other women that the famous person used the same distinctive m.o. in raping or sexually assaulting them. Conversely, if no one comes forward with similar claims of sexual misconduct, we can safely dismiss the initial claim as mistaken.

That explains why I have dismissed both the claim of Dr. Ford against Justice Kavanaugh and the claim of Ms. Reade against Vice President Biden as unworthy of serious consideration as I evaluate the character of a Supreme Court Justice and a candidate for President, respectively. In each case, no one has come forward with even remotely similar claims of sexual misconduct. In the case of Justice Kavanaugh, two other women came forward with claims of misconduct, but neither claim withstood even the most superficial press investigations. In the case of Vice President Biden, the only other claims of sexual misconduct alleged that he sometimes engaged in unwanted and uninvited hugging—a relatively benign pattern of behavior that he has acknowledged and vowed not to continue.

In summary, while there are no rules of law that apply to the process of evaluating claims that public officials engaged in sexual misconduct, we can use a combination of the rules of law applicable to cases in which judges and juries decide whether someone committed a sexual offense and our experience in applying those rules as helpful guides in the process of evaluating claims that candidates for office engaged in sexual misconduct.  

Richard J. Pierce, Jr. is the Lyle T. Alverson Professor of Law at GW Law