Watch CBSN Live

Sanity In The Yates Case

Attorney Andrew Cohen analyzes legal issues for and CBS News.
To understand how and why Andrea Yates' murder conviction was overturned Wednesday, you have to understand just how much the testimony of Park Dietz meant to the prosecution's case against the Houston mother.

Dietz, the famous forensic psychiatrist, told jurors that Yates was not legally insane when she drowned her five children, one by one, in the bathtub of their home. He told them that Yates knew right from wrong before, during and after the killings. Of all the expert witnesses who testified during the trial, only Dietz brought with him to the stand the sort of swagger and mock certainty that any lawyer craves in an expert witness. When testifying, he talked to the jury with the credibility of a judge. He was smooth. He was polished. He seemed worth every bit of the big money he undoubtedly earned to try to convince the jury that Yates deserved punishment, not mental health treatment.

Without Dietz's conclusions, prosecutors would have been left with the audiotape of Yates' 911 call to the police and with other evidence that showed Yates to be obviously and severely mentally ill. And with that evidence, alone, Yates quite easily could have been found not guilty by reason of insanity. After all, the act itself — drowning your sweet, innocent children in the name of God — is insane per se. It was Dietz who tied together the disparate pieces of the prosecution's case; it was Dietz who gave support and meaning to the prosecution's theory that Yates knew precisely what she was doing.

It was Dietz who gave jurors the moral cover they needed to send Yates to prison despite her mental condition. The Texas Court of Appeals noted the impact of Dietz's testimony in its ruling. "Five mental health experts testified" that Yates" did not know right from wrong or that she thought what she did was right," the panel unanimously found. "Dr. Dietz was the only mental health expert who testified that" Yates "knew right from wrong. Therefore, his testimony was critical to establish the State's case."

I give full credit to the appellate judges for recognizing Dietz's vital role in the outcome of the case and for acknowledging that an important part of his testimony was made up. The Texas criminal justice system has taken plenty of flak recently — including from gadflies like me — but this is one instance in which the system worked. Whether you are in Texas or anywhere else, you simply cannot convict someone of a capital crime based upon important testimony that turns out to be undisputedly false. I also give credit to prosecutors for immediately revealing the problem and to Dietz, for promptly conceding his mistake.

What was the mistake? Dietz falsely told jurors that as a consultant for the show "Law & Order" he knew "that there was a show of a woman with postpartum depression who drowned her children in the bathtub and was found insane and it was aired shortly before the crime occurred." Prosecutors then used that statement as gospel during the cross-examination of a key defense expert witness, essentially forcing Dr. Lucy Puryear to concede that the show, and the timing of it, might have been relevant to Yates' state of mind. Then prosecutors compounded the error by using the "Law & Order" story in their closing argument.

Problem is, no such episode ever aired or was produced. The folks from the television show called Yates' attorneys and told them that Dietz had made a mistake in referencing an episode like that. Deitz then acknowledged his mistake but all of this came after the jury had quickly come back with a guilty verdict against Yates. We may never know precisely how and why Dietz thought the show had aired or had even ever been produced. What we do know is that the mistake was important and fairly inexcusable. Dietz or prosecutors or both should have tracked down the story to verify it before using it as part of the case against Yates. This is the precisely the sort of trial sloppiness that appellate courts are designed to fix.

On appeal, prosecutors argued that Dietz's testimony about the television show was not material — that "there is no reasonable likelihood" that the testimony could have "affected the judgment of the jury." But, as the appeals court noted, prosecutors did not "make any argument to support such a conclusory statement" and, indeed, there really isn't an argument to be made. If the "Law & Order" bit weren't important, prosecutors would not have solicited it from Dietz, he would not have discussed it, prosecutors would not have used it to undercut defense witnesses, and attorneys for both sides would not have talked about it during closing arguments. The testimony about the television show allowed prosecutors to argue that the killings had been deliberate and premeditated and that Yates had even plotted out her defense before she committed the crime.

So what does all of this mean to Yates? Not much. She is still severely mentally ill and will probably need major treatment for the rest of her life. Even if she had initially been found not guilty by reason of insanity she would have gone to a mental health hospital and not been allowed back into society. None of that changes with this reversal. She will not go free whether she is re-tried or not. And now prosecutors have a few choices to make. They can appeal this reversal up the ladder through the Texas appellate system. They can simply accept this result and retry Yates. They can try her for the first time for two of the killings that were not a part of the original case. Or they can simply drop the matter, save their own time and taxpayer money, and allow Yates to be treated as insane but not as a premeditated criminal.

If Yates ultimately is tried again, it's a crapshoot as to whether a new jury would convict her. First, we'd have to know whether Dietz would be allowed (by prosecutors, the defense or the judge) to testify again as an expert witness for the prosecution. Then we'd have to know whether Dietz's testimony would have the same impact it did the first time around without the "Law & Order" red herring. The passage of time also might impact the jury's view of Yates and her conduct. After all, a Texas jury in the interim found Deanna Laney not guilty by reason of insanity after she beat her two children to death with a rock in the front yard of their home. Maybe that's a sign that the insanity defense still has resonance, even in hardcore law-and-order places like Texas.

Whether you agree with the ruling or not, the Yates case now finds itself again at a crossroads. The last time we were here, we sent a terribly ill woman to prison to spend the rest of her days either in conscious torment for her deeds or in a Haldol-induced bliss that blocks out the horror of her actions. Perhaps the players involved can do better this time.

By Andrew Cohen