In another “sexual abuse” opinion by Judge Pigott, the Court of Appeals, as it did in People v Diaz (decided the same day), determined the expert’s testimony about Child Sexual Abuse Accommodation Syndrome, which included explanations about how an abuser gains the trust of the victim and encourages secrecy, etc., was admissible.  But here the prosecutor followed up the expert’s general testimony with hypothetical questions which mirrored the victims’ testimony.  The Court of Appeals determined the hypothetical questions constituted improper bolstering (but held the testimony to be harmless error under the facts):

We agree with defendant …that the expert’s testimony exceeded permissible bounds when the prosecutor tailored the hypothetical questions to include facts concerning the abuse that occurred in this particular case. Such testimony went beyond explaining victim behavior that might be beyond the ken of a jury, and had the prejudicial effect of implying that the expert found the testimony of this particular complainant to be credible – even though the witness began his testimony claiming no knowledge of the case before the court.  People v Williams, 53, CtApp 3-26-13