The Strange Case of Andrea Yates and Dr Park Dietz

Abstract

Following the erroneous testimony of a celebrated expert witness, a mentally disturbed mother was convicted of murdering her five children. The witness’s evidence was the foundation for an inference that the defendant had concocted an insanity defence based upon a popular television drama series episode. In fact, the expert had “falsely remembered” a non-existent episode of the series. The conviction was reversed upon appeal on the sole ground of the witness’s erroneous testimony. Upon re-trial, the defendant was found not guilty by reason of insanity.

Keywords: Texas, criminal law, murder trial, expert, testimony, witness, forensic, “Law and Order” television series, mother, infanticide, appeal, post partum psychosis, insanity defence, psychiatric evidence, psychiatric disorder, mental, witness error, false memory, expert fallibility, false evidence