Controversial Psychiatrist in Yates Case Speaks Out

The psychiatrist whose testimony helped convict Andrea Yates in the slayings of three of her children -- and was the basis for an appeals court's decision to overturn the convictions -- says he made a mistake, but still believes the Texas mother was sane when she killed her children.

"I don't think there's any question about that [Yates' sanity]," Dietz said in an interview on "Good Morning America" today. "The evidence that she knew right from wrong is what she said. She says in recorded statements, including my interviews, that as she killed her children, she knew that it was wrong to do it. She knew God would disapprove. And she knew society would disapprove. That's the evidence. With that kind of smoking gun evidence that she knew it was wrong, it would be silly to make up something else."

On Thursday, a three-judge panel of the First Court of Appeals in Houston overturned Yates' capital murder convictions for the 2001 slayings of three of her five children and ordered a new trial. (Yates had confessed and pleaded guilty to killing her other two children.) In its ruling, the panel cited the false testimony by Dietz.

Yates' defense argued that she was insane when she killed her children and was incapable of realizing that her actions were wrong. Dietz said he based his conclusion that Yates was sane in part on Yates' belief that Satan, not God, had ordered the murders. But Dietz incorrectly testified that an episode of "Law & Order" dealing with postpartum depression aired just before the killings, inferring that Yates was inspired by the show. Dietz, a consultant for "Law & Order" at the time, told jurors the episode portrayed a woman who drowned her children and was later found not guilty by reason of insanity.

An Honest Mistake

Producers from "Law & Order" called Yates' attorney and said such an episode didn't exist. Yates' attorney called for a mistrial but his petition was denied and Yates was convicted. Prosecutors admitted the "Law & Order" mistake, saying it was unintentional, and a grand jury later cleared Dietz of perjury allegations.

Today, Dietz said he made an honest mistake when he referred to the nonexistent "Law & Order" episode and tried to correct his error immediately.

"I made an honest mistake about the television show during cross-examination, and a week later I learned that I might be mistaken," Dietz said. "I immediately researched it and that same day offered to fly back to Houston during the trial and correct the error. I was told just to put it in writing, and I wrote a detailed letter, sent it to the prosecution. They gave it to the defense, and unfortunately it wasn't put into the record. So the three-judge panel didn't have access to the full story."

Dietz said that prosecutors first told him there was a "Law & Order" episode dealing with postpartum depression in a conversation before the trial. He said he made notes during the conversation and that he confused his memory of the notes with the memory of the show. However, prosecutors told ABC News that they never mentioned the episode to Dietz.

The Larger Insanity Issue

George Parnham, Yates' attorney, disputed Dietz's insistence that Yates was sane at the time of the killings because, he said, the psychiatrist interviewed her after she had been on medication for months. He said he would not seek Yates' immediate release from prison because she still needs to receive treatment and a change of environment would be too disruptive and potentially traumatic.

Despite the appeals court's call for a new trial, Parnham said the real issue Yates' case illustrates is the need for the Texas justice system to rethink the way it defines insanity.

"The logical mistake [by Dietz] is really not the issue that we need to deal with," Parnham said. "What we need to deal with is the present state of mental health as it's being considered by the mental health community and the legal system in this community."

Two weeks before she killed her children, Yates was released from the hospital. She had struggled with postpartum depression for two years, since the birth of her fourth child, doctors said. In 2003, Yates was placed on suicide watch while in prison. At the time, Yates believed her dead children were in purgatory and only her death would free them, Parnham said.

In July, Yates was hospitalized after refusing to eat. Her mother, Karin Kennedy, told "Good Morning America" that Yates starved herself around the anniversary of the killings. Yates, Kennedy said, appears to be more mentally stable when she is on medication. However, every time her daughter appears to get better, Kennedy said, her medication is reduced -- and she becomes less stable.

"It seems like whenever she gets better they take away some of the medication, because it does have side effects," Kennedy said.

Prosecutors said they would seek another hearing before the Texas First Court of Appeals, and if necessary continue their appeals in higher courts. It may be years before Yates' retrial in the slayings of her children takes place.