Court Hears Appeal by Andrea Yates

Andrea Yates' (search) murder convictions for drowning her children should be overturned because the state's expert witness gave false testimony about working on a nonexistent episode of "Law and Order" (search), her attorneys told a state appeals court Tuesday.

Yates was sentenced to life in prison in the 2001 deaths of three of her children after jurors rejected her insanity defense. She was not tried in the deaths of the other two. Psychiatrists testified that Yates suffered from schizophrenia and postpartum depression.

Her attorneys told a three-judge panel of the appeals court that she deserves a new trial because of 19 errors that were committed in her 2002 trial.

Yates' attorney Troy McKinney focused on expert witness Park Dietz (search), who McKinney said "told a whopper of a falsehood" when he said he consulted on an episode of the TV show "Law and Order" involving a woman found innocent by reason of insanity for drowning her children.

Dietz testified the episode aired shortly before the drownings, and testimony during the trial indicated Yates was a viewer of the series.

After jurors found Yates guilty, attorneys in the case and jurors learned that no such "Law and Order" episode existed.

McKinney called the testimony the "dynamite" that had turned the tide of the trial against his client.

Prosecutors said there was no evidence that Dietz intentionally lied, and that he did not suggest that Yates used the episode to plan the killing.

"There was a great deal of other evidence which revealed that (Yates) planned and/or premeditated her killing of her children," prosecutor Alan Curry wrote in his response to the appeal.

Yates' attorneys also claim the Texas insanity standard, which required the defendant prove she did not know her actions were wrong, is unconstitutional because it does not define the words "know" and "wrong."

Yates' husband, Russell, who attended Tuesday's court session, filed for divorce earlier this year.