The woman who told police she drowned her five children in her Houston home Wednesday would be employing a risky but occasionally successful defense if she told the court she had acted because of postpartum psychosis.
"It's a very rare case where this type of defense is successful. It's not guaranteed to persuade a jury," said Laurie Levenson, a professor at Loyola Law School in Los Angeles.
Andrea Yates, 36, has been charged with capital murder in the deaths of her children, but prosecutors in Harris County, Texas, have said that they are just beginning their investigation and that they may change the charges and the penalties sought.
While Yates' defense strategy is unknown, her husband told reporters that she suffered from postpartum depression after the birth of their fourth child two years ago and after the birth of their fifth child six months ago.
Russell Yates also said his wife had once attempted suicide, was taking medication and that a list of techniques had been posted in their home to help her deal with stress.
Police say the children were drowned one by one in the Yates' bathtub. They say Andrea Yates called police to the home and then admitted to the killings when officers arrived.
The children were Noah, 7; John, 5; Paul, 3; Luke 2; and Mary, 6 months.
Levenson said several factors suggested that Yates' lawyers would likely pursue an insanity defense based on postpartum psychosis, the most extreme form of postpartum depression.
Those factors included Yates' history of depression, the extreme and almost incomprehensible nature of the crimes and Yates reportedly relating the killings to authorities in a "zombie-like fashion," the Houston Chronicle reported Friday.
Dr. Saul J. Faerstein, a forensic psychiatrist in Los Angeles, said that Yates would probably succeed with a postpartum psychosis defense if the case were tried before a California jury.
"You have credible evidence of prior mental illness, so that's going to help her," Faerstein said. "Most jurors would look at this family as an intact, loving family. I'm speculating that there would be a lot of testimony that she was caring. So, they'll think there's no other reason for her to do this egregious thing other than she's crazy."
However, Levenson said, the defense would be a risky one.
"Some jurors' reactions will be, 'Oh, my God, it's such a horrible crime that she has to pay for it,' " Levenson said. "And some jurors will have the opposite reaction: 'It's such a horrible crime, she must have been out of her mind.' "
At the same time, Levenson said, women who previously tried the defense have sometimes reduced the severity of the charges or the punishment they faced.
In one unusual case, a California Superior Court judge in 1988 reversed a jury's murder verdict against an Orange County woman who had driven a car over her infant son. Instead, the judge found the woman, Sheryl Lynn Massip, not guilty by reason of insanity because of postpartum psychosis.
In 1998, a Colorado judge found Bethe Feltman not guilty by reason of insanity and ordered her committed to a state mental hospital after the killing of her two small children. According to press reports at the time, the woman had told psychiatrists that she had been depressed since the birth of her daughter and that killing the 3-month-old girl and her 3-year-old son was the only way to get relief.
A postpartum defense was used this year. Judy Kirby was accused of killing seven people by driving the wrong way on an Indiana highway. Kirby's attorney sought unsuccessfully to have her declared incompetent to stand trial. The attorney said Kirby was suffering from postpartum depression after a birth five months before the crash.
Postpartum depression, or the "baby blues," affects an estimated 75% of mothers after childbirth, said Diana Lynn Barnes, a Woodland Hills psychotherapist who specializes in pregnancy and postpartum issues. The symptoms include irritability, tearfulness, anxiety and fear of not being able to cope.
Women suffer its severe form, postpartum psychosis, in one or two out of 1,000 births, Barnes said, though not all cases involve violence. "One symptom in these cases is that women are feeling disconnected and disengaged from their infant," she said. "The attachment relationship has been disrupted. So, people say how could a woman do such a thing--she wasn't in her right mind. If you have a postpartum psychosis, the brain chemistry has gone awry."