Updated

A psychiatrist who interviewed Andrea Yates after she drowned her five children testified Friday that she recalled them struggling as they died, except for her 6-month-old daughter, Mary.

"She wasn't strong enough," Yates told Park Dietz during a Nov. 7 interview. She also said her oldest child, 7-year-old Noah, said something to her.

"I don't know if it was 'I'm sorry' or not," Yates said.

Dietz was on the stand for a second day of rebuttal testimony for the prosecution, which is attempting to show Yates was sane when she killed her children and should be convicted of capital murder. Yates has pleaded innocent by reason of insanity.

While Dietz said Yates knew her actions were wrong in the eyes of the law, society and God, he would not give an opinion whether she met the definition of legal insanity.

He said Yates called police immediately after the June 20 drownings because she knew her actions were wrong. He said she told him she had decided to kill the children the night before and that she "needed to go ahead and do it."

Defense witnesses have argued that psychosis drove Yates to kill. She told Dietz she believed her children were regressing behaviorally and said Satan ordered her to kill her children to save them from damnation.

"The fact that she regards it as coming from Satan is the first indication that she knows this is wrong," Dietz said. "She doesn't think this is a good idea that comes from God. She thinks it is an evil idea that comes from Satan."

Dietz said Yates didn't seek out a priest or minister, call the police, send her children to a safe place or attempt suicide to try to save her children.

"I do expect people with delusions of imminent harm to act as if that is true and protect the ones they love," said Dietz, who has worked on other high profile cases including that of serial killer Jeffrey Dahmer, Unabomber Ted Kaczynski and South Carolina child killer Susan Smith.

Dietz said Yates kept thoughts about killing her children a secret because she feared she would be stopped.

"Ordinarily when someone keeps a criminal plan secret they do it because it's wrong," he said.

During their interview, Dietz asked Yates why Satan would want her to do something that would save her children from hell. She said the deaths would result in her being condemned.

"You saw it as a sin you were going to commit?" Dietz asked Yates.

"Yes," she replied.

"Did you struggle against doing it?" the psychiatrist asked.

"No," Yates told him.

Dietz said Yates became confused and sometimes changed her story during the interview. He thought the changes came because Yates was still depressed and likely suffers from schizophrenia.

Dietz said a note in Yates' medical records showed Dr. Mohammad Saeed told her husband, Russell, in April that she should not be left alone.

"When you have a mother who is this severely impaired, someone has to be with her at all times," Dietz said. "It isn't safe to leave her with the children."