Rationality Within Irrationality

CBSNews.com Legal Analyst Andrew Cohen is in Houston, covering the trial of the mother who drowned her five young children, and offering his expert analysis.

Yates' lawyers want jurors to believe that she was psychotic when she killed them.

That's essentially what this case comes down to as it winds toward closing arguments. And if jurors frame the question of the case this way, Yates has a decent chance of being acquitted by reason of insanity. It seems to me that most people would rather think that a psychotic mother killed her children than they would like to think that a non-psychotic mother killed her children.

That's the big dilemma for the State as it winds up its rebuttal case on the issue of whether Yates was legally insane last June 20 when in the span of about a half hour or so systematically destroyed her family.

The nature of the act is so insane — a loving mother kills her kids! — that it almost speaks for itself. How could a non-psychotic mother do that? How could a mother who knew such despicable acts were wrong still do them? And is it possible to snap from depression to psychosis within the span of a few hours, which is essentially what Dr. Park Dietz, the famous forensic psychiatrist, told jurors Friday?

Dietz finished up his direct examination Friday morning and before he was through, he had taken the jury through a detailed list of the reasons he thinks Yates knew right from wrong at the time of the killings.

That's central to the case because it is an element of Texas' insanity law and prosecutors aren't contesting the other key element: that the person committing the act has a "mental disease or defect."

Dietz told jurors in assured tones that Yates exhibited "knowledge of wrongfulness" before the killings, during the killings and after the killings. His presentation was smooth and his graphics-everyone likes graphics these days-were easy to read and follow.

More importantly, perhaps, prosecutors through Dietz's testimony were able to show jurors a videotape the doctor made with Yates last November, roughly five months after the killings, in which the defendant offered bone-numbing detail about how her children died that morning.

"Mommy are we going to take a bath today?" her little boy, Paul, asked as his mother drew the water that would kill him. Noah, the eldest and last to die, asked his mother if he had done something wrong as she forced him under the water.

Yates herself, on the video, cried through her psychosis when she told this to Dietz in November. In the courtroom Friday, some jurors wiped their faces. So did Yates' mother, Jutta Karin Kennedy, who had never before seen or heard the description of how her grandchildren died.

Prosecutors played the tape — and Dietz focused upon it — because they wanted to talk to jurors about why they think Yates knew it was wrong to kill even as she killed.

How did Dietz reach this conclusion? Because Yates appeared to cover each body between homicides in order, Dietz supposed, to conceal the previous homicide from the surviving children. Also, Dietz told jurors, Yates didn't try to comfort the children during the killings as he would have expected her to do if her real aim, as she has always maintained, was to ensure their place in heaven after their deaths. "I would expect her to comfort the children by telling them they would be with Jesus or they would be with God," Dietz told the jury. But Yates said no such thing that morning.

Earlier, Dietz had told jurors that Yates knew it was wrong to kill the children even before she did it. He came to this conclusion, he said, because even if Yates thought the children were threatened by Satan, which is one of the ways Yates has put it, she didn't try any "non-lethal" way of getting them help. Yates didn't take the children to a religious leader and she didn't even tell her husband, Russell, about the satanical "presence" she felt.

Dietz also told the jury that Yates didn't tell her husband about her plans for the children even though she had thought about drowning them for a month and then made sure to act all right on the morning of June 20 so as not to arouse any suspicion on Russell's part.

After the killings, Dietz said on direct examination, Yates clearly showed that she knew what she had done was wrong by covering the bodies "indicating guilt or shame." And then she called the cops, Yates told Dietz on the tape, "because that's what you do when you've done something wrong."

When it was all done, he concluded, Yates' depression quickly turned into severe psychosis so quickly that by the time Dr. Melissa Ferguson interviewed Yates the next day, she was completely gone.

How did it happen so quickly? Dietz says that the "stressor" of losing her children, in combination with her arrest and her detention in a mental facility, turned Yates's mental health from bad to worse. Killing the children, in other words, made her insane. Aside from that, Mrs. Lincoln, how was the play?

Yates' attorneys get their crack at Dietz Saturday and it ought to be a real donnybrook. There are so many questions to ask and so few chances to ask them.

Here is a short list of the ones I'd ask:

If Yates wasn't psychotic on June 20, for example, then why did she do it? Dietz certainly didn't say during his direct examination, although his testimony Thursday suggests that he is ready to point a finger at Russell.

And why isn't it reasonable for the jury to assume that Yates made the decisions she did before and on June 20 because she was psychotic? I mean, why should Dietz necessarily be attributing rational and intentional thought to a person who, if nothing else, was severely depressed and schizophrenic at the time?

Great expert witnesses make their bones during cross-examination and now the great Dietz will have his chance once again.

By Andrew Cohen