Rebuttal Lacks Bite

The final day of rebuttal testimony from the prosecution's expert witness, Dr. Park Dietz, in the Andrea Yates trial was rather anti-climactic according to CBSNews.com Legal Consultant Andrew Cohen. Cohen also previews the defense's next move.

George Parnham, the genial but effective defense attorney, didn't make a frontal assault on the key conclusion by Dr. Park Dietz, the expensive but effective forensic psychiatrist, that Yates knew her conduct was wrong when she drowned her five children last June 20th. And Dietz didn't take the opportunity during the cross-examination or on the state's re-direct examination to say anything more damaging to the defendant's insanity defense.

It was as if both sides agreed to count their gains and cut their losses and slowly back away.

Even though Dietz still refused to offer an opinion on the ultimate issue of whether Yates was legally insane at the time of the killings — he says, rightfully, that's for the jury to decide — his testimony still is enough to convict Yates because it goes to the heart of one of the key elements — knowledge of wrongfulness in Texas' insanity statute.

So the job for Parnham Saturday was to chip away at Dietz's investigative methods and experience just enough so as to open the door a bit on his reliability as an expert in the case. Parnham knew enough, apparently, not to try to outwit or overwhelm or even argue with Dietz on the stand. Instead, he scored the few points he could and sat down before Dietz could reinforce his direct testimony.

First, Parnham got Dietz to concede that Yates had a "severe mental disease or defect" — probably schizophrenia, Dietz opined -- at the time of the killings. That's crucially important, too, because it is the other key element in the Texas insanity law everyone is fighting about in this case. By getting Dietz to make this conclusion, the defense essentially proves that element by a preponderance of the evidence. It's called consolidating your victories and that's what Parnham did first before he sparred with Dietz over the more contentious issues between them.

Turns out, we now know, that Dietz's examination of the record wasn't as exhaustive as he had suggested it was during his direct testimony. Dietz never talked, for example, to Dr. Mohammed Saeed, Yates' treating doctor at the time of the killings, whom you would think would be in the best position of all to discuss how Yates was acting and what she was saying in the days before June 20th. Indeed, Saeed treated Yates two days earlier, on June 18th, and while he completely underestimated the nature and extent of Yates' mental illness, you would think that Dietz would have wanted to chat.

For that matter, Dietz never talked to a doctor who recommended electro-shock therapy for Yates as far back as 1999. And although he tried, he never spoke with Russell Yates, Andrea's husband, or with Dora Yates, Andrea's mother-in-law, both of whom obviously would offer a lot of insight into the defendant's state of mind at the time. And Dietz hadn't even heard of Randy Yates, Russell's brother, who says that Andrea Yates was "totally disconnected with reality" last spring.

Parnham also got Dietz to tell jurors that he hasn't actually treated a patient in 20 years and hasn't actually treated a patient with post-partum depression in 25 years. That's important because it contrasts Dietz unfavorably with defense expert Lucy Puryear, who testified last week that Yates didn't know right from wrong when she killed.

Puryear is a specialist in women's mental health issues. Dietz's concessions also play into an image of him as a "hired-gun" who is so busy managing multi-million-dollar consulting businesses (he's charging the State $500/hour) he doesn't really have the time to be a real, working doctor anymore. If jurors have that image of Dietz when they deliberate, they very well may discount his testimony.

That's about it on the Dietz front. He came. He talked. He opined. He was impressive but far from perfect; important but far from decisive.

And now the defense has a final turn at bat and it clearly has some work to do to close some holes opened up by the prosecution's rebuttal testimony. First, the defense may have to recall Dr. Melissa Ferguson, a jailhouse doctor who interviewed Yates about 24 hours after the killings.

On Saturday, Yates' jailer at the time, Deputy Michael Stephens, told jurors that Yates told Ferguson: "I knew what I was doing was wrong." If it's true, that statement, made by the defendant so soon after the drownings, is very damaging to the insanity case Yates' lawyers are trying to make.

In addition, before his credibility was damaged on cross-examination by Parnham, Stephens also told jurors that Yates said on June 21st that "I only had to kill one to justify all of them" and that her husband, Russell Yates, "didn't want a girl. He wanted another boy for a basketball team."

Little Mary Yates, a six-month-old, was the fourth Yates' child to be drowned. Testimony by Dr. Ferguson that she doesn't recall Yates saying such things — or even better, an affirmative declaration by the doctor that Yates did not say such things — would greatly help the defense case.

Yates' attorneys are also going to have to bring back at least one or two of their own experts to answer questions raised by Dietz's testimony.

First, the defense has to respond to the notion by Dietz that Yates only became "grossly" psychotic after the killings and her imprisonment. It also has to reinforce the notion that all of the comments Yates made about "knowing it was wrong" — comments upon which Dietz placed great significance -- came either during a time when she was severely psychotic or when she was getting better but couldn't possibly have an accurate memory of what she really was thinking.

Yates' lawyers are sure to play more excerpts of her videotaped interviews for their surrebutters. The key to the defense now is getting jurors thinking that Yates's words are less important than the way she looks on all those videotapes. If the defense can accomplish that, it'll be in decent shape as the case goes to closing arguments.

By Andrew Cohen