People v. Alexander

Summary

The Court held that an expert's diagnosis of a child with "medical torture" was inadmissible because it did not help the jury evaluate a fact in issue, lacked a reliable foundation as to psychological maltreatment, and risked substituting a medical label for the jury's determination of criminal responsibility. Because the defense did not object, the Court applied plain-error review and affirmed the convictions, concluding that the strong untainted evidence prevented Alexander from showing that the error affected the trial's outcome.