Prosecutors who charge defendants with sex offenses involving minors sometimes base their prosecutions solely on the alleged victim’s testimony. Fearing that a jury will doubt that testimony, prosecutors often bolster their cases with expert witnesses.

In some cases, expert testimony is uncontroversial. A physician who examines a child and discovers wounds that were likely caused by sexual contact may contribute valuable testimony to the prosecution’s case. Defense experts who highlight other potential causes of the wounds also provide important evidence for the jury’s consideration.

Psychologists are frequently asked to explain why a minor might delay reporting a sexual assault. Delayed disclosure might be evidence of fabrication, but peer-reviewed literature suggests that children might delay disclosure of sexual victimization for a variety of reasons. Courts routinely permit qualified experts to explain those reasons in cases where an alleged victim did not immediately report the sexual contact.

More problematic is testimony about how a minor might react to a sexual assault. While the testimony might be admissible if it’s supported by evidence beyond the expert’s anecdotal observations, an expert must take care not to vouch for the victim’s story. In other words, a neutral expert should not say or imply that a complaining witness must be telling the truth about an alleged sexual assault because she behaved in the way the expert would expect a sexual assault victim to behave.

Responses to sexual assaults, like responses to other stressors, vary widely. When experts attempt to testify that delayed reporting or specific behaviors are evidence of a sexual assault, they cross a line that comes dangerously close to vouching for the child’s story. Juries understand such testimony to mean that the expert believes the child. But experts are not lie detectors, and whether the expert believes the child is not relevant evidence. Whether the jury believes the child is the ultimate question.

Child Sexual Assault Accommodation Syndrome

A recent case in New Jersey addressed an expert’s testimony about Child Sexual Assault Accommodation Syndrome (CSAAS). The syndrome is the controversial brainchild of Roland Summit, who theorized that sexually abused children behave in certain ways that include making a delayed disclosure of a sexual assault, followed by a retraction of the disclosure.

Some prosecutors misused CSAAS as a diagnostic tool. Whenever children behaved in a certain way (such as demonstrations of “secretiveness” and “helplessness”), prosecutors argued that their behavior corroborated their sexual assault accusations. Unfortunately, since abuse victims (like children who have not been abused) behave in a variety of ways, almost any behavior can be portrayed as corroborative evidence of abuse, rendering the alleged corroboration meaningless. Prosecutors also used CSAAS to argue that any subsequent retraction of an accusation must have been false because abuse victims can be expected to retract their accusations.

Even Summit admitted that CSAAS is not a diagnostic tool. He cautioned against misuse of his theory as evidence that a child’s accusation is truthful. Unfortunately, his statements fell on deaf prosecutorial ears.

A 2008 study noted that the CSAAS “theory has had a tremendous impact on the field of [child sexual assault] forensic evaluations, despite its dearth of empirical support.” While that study found support for the finding that some assault victims delay reporting, it found very little evidence that victims are likely to recant accurate reports of sexual assaults.

New Jersey v. Librado

Aurelio Librado lived with his partner, their three children, her two children by a different relationship, and his brother’s family. Two or three dozen people came to Librado’s home for a party that celebrated his nephew’s first communion. The nephew’s godmother attended the party with her 15-year-old daughter, L.A.

L.A. testified that Librado forced her to leave the party, brought her to the basement, touched her breasts, and made unsuccessful attempts to have vaginal and anal intercourse with her.  When he let her go, she went to the bathroom and found a substance she believed to be semen on a tissue she used to clean herself.

One of Librado’s stepsons saw L.A. crying. When he asked her why, she said “your stepfather sexually violated me.” The stepson did not believe L.A. and did not repeat the accusation to anyone until the police questioned him a year later. L.A. testified that she did not tell her mother what happened because she was embarrassed and did not want Librado’s children to grow up without a father.

In the following months, L.A.’s mother noted changes in L.A.’s personality. She eventually began to cut herself. When her mother threatened to make her see a psychiatrist, L.A. stated that she had been sexually violated. She refused to discuss details or to identify her assailant.

L.A.’s parents contacted the police, who noted L.A.’s acts of self-harm and had her hospitalized. L.A. persisted in refusing to identify the person who sexually assaulted her. A month later, L.A. told her godmother where and when the assault had occurred. A month after that, L.A. identified Librado during an interview by a child interviewer specialist employed by the prosecutor’s office.

Dr. Brett A. Biller testified about delayed disclosure and CSAAS. Several witnesses testified about L.A.’s attendance at the party, her post-party behavior, and her hearsay accusations. Librado’s stepson testified about the statement that L.A. made to him at the party. A jury convicted Librado of several sex offenses.

Expert Testimony Regarding Delayed Disclosure

Under New Jersey law, an expert may testify about the reasons children delay disclosing a sexual assault if that testimony would assist the jury. New Jersey courts have concluded that the testimony only assists the jury if the alleged victim cannot provide a rational explanation for delaying disclosure.

In this case, L.A. explained that she did not disclose the assault because she was embarrassed and did not want to harm Librado’s family. That explanation was easy for a jury to understand. Explaining why other children in other circumstances might delay disclosure provided no additional assistance to the jury. Accordingly, expert testimony as to delayed disclosure should not have been admitted.

Expert Testimony Regarding CSAAS

Dr. Biller testified that CSAAS was designed by “advocates for children,” a claim that only renders the syndrome more suspect. Unbiased experts are advocates for the truth. The jury, however, was likely impressed by the suggestion that an expert who was trying to protect children came up with a way to do so.

Dr. Biller also testified that “CSAAS helps to explain how children’s behavior might lead someone to believe they were not victims, when in fact they were.“ Dr. Biller explained in great detail and depth the various behaviors that might mislead an adult into thinking no abuse occurred.

Apart from being ungrounded in actual science, none of that testimony had the slightest relevance to the case. J.A. never claimed she was not a victim. She simply didn’t want to talk about it. Nor did she engage in any behaviors (apart from silence) that might have misled adults into thinking that no abuse occurred. Rather, her personality changes and self-harming behaviors cried out for an explanation.

New Jersey has previously ruled CSAAS testimony inadmissible except when necessary to explain delayed disclosure. Since it was not necessary for that purpose in this case, the jury should never have heard from Dr. Biller. And since Dr. Biller’s testimony (as well as inadmissible hearsay) may have affected the verdict, Librado’s conviction was reversed and the case was remanded for a new trial.