HOUSTON – Andrea Yates suffered from a severe mental illness last year when she drowned her five children in the bathtub, but still knew right from wrong, a forensic psychiatrist hired by the state testified Thursday at her murder trial.
"She thought killing the children was sinful," said Dr. Park Dietz. "If you know it's a sin, then you know it's wrong."
Defense witnesses have testified that Yates suffered from delusions and believed the only way to save her children from hell was to kill them. But Deitz said Yates didn't seek out a priest or minister, call the police, send her children to a safe place or attempt suicide.
"I do expect people with delusions of imminent harm to act as if that is true and protect the ones they love," he said.
Dietz said Yates kept her thoughts about killing her children secret because she feared others would stop her: "Ordinarily when someone keeps a criminal plan secret they do it because it's wrong."
Yates, 37, who has pleaded innocent by reason of insanity, faces murder charges in the drownings of 7-year-old Noah, 5-year-old John and 6-month-old Mary. Charges could be filed later in the deaths of Paul, 3, and Luke, 2. She faces life in prison or the death penalty if convicted.
Defense attorneys are trying to show Yates didn't know right from wrong last June 20 when she drowned her children.
Dietz, who has testified in other high-profile trials such as the Unabomber and South Carolina child killer Susan Smith, was among rebuttal witnesses presented by prosecutors. The defense rested its case Wednesday.
During a Nov. 7 videotaped interview that was played in court Thursday, Deitz asked Yates why Satan would want her to do something that would save her children. Yates replied that it was because the killings would result in her being condemned.
"You saw it as a sin you were going to commit?" Dietz asked.
"Yes," she replied.
"Did you struggle against doing it?"
"No," Yates said.
Dietz said Yates seemed confused at times during the interview, conducted over two days, and said he believes she is still depressed and likely schizophrenic. Earlier, Yates told the psychiatrist the idea to kill was hers alone and not Satan's.
The psychiatrist said he found a note in Yates' medical records in which a doctor advised her husband not to leave her alone. Dietz said leaving her with the children gave her the opportunity she needed.
"When you have a mother who is this severely impaired, someone has to be with her at all times," Dietz said.
Dietz said several things contributed to Yates' condition, including her refusal to take her medicine and her efforts to home-school her children inside a converted bus where the family lived in 1999.
Earlier, a store owner who sells home-schooling materials for parents said she saw Yates' demeanor change quickly last year when she asked Yates about having more children. Terry Arnold said she became friendly with Yates in the months before the killings.
"I felt like I hit a sore subject," Arnold said. "There was a change in her demeanor very quickly. It was just sadness. I thought she was going to cry."
Arnold said she first met the Yates family early last year and perceived Yates as a loving mother. A couple of weeks before the killings, however, Yates seemed disheartened.
"She was not as lit up from the inside," Arnold said. "There was a flatness there."