Andrea Yates stared at her cell wall the day after she drowned her five children in a bathtub and appeared to be talking to someone who wasn't there, a psychiatric nurse testified Friday.

John Bayliss, who worked in the mental health unit of the Harris County Jail, testified in Yates' second murder trial that the suburban Houston woman slowly turned to look at him only after he repeatedly called out her name. She then turned back to the wall and continued rapidly mumbling and picking at her hair, he said.

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"(It) is something I had not observed in any other patient I had dealt with," Bayliss said.

Yates was convicted of murder in 2002, but the conviction was overturned last year because of erroneous testimony. She has again pleaded innocent by reason of insanity.

Dr. Melissa R. Ferguson testified Thursday that she evaluated Yates the day after the children — 6-month-old Mary, 2-year-old Luke, 3-year-old Paul, 5-year-old John and 7-year-old Noah — were drowned in their home in June 2001. Ferguson, then the medical director of psychiatric services at the Harris County Jail, said Yates at first showed no emotion but then started crying and yelling.

"She screamed, 'Couldn't I have killed just one to fulfill the prophecy? Couldn't I have offered Mary? Are they in heaven?"' Ferguson said.

Ferguson testified that Yates said her children were not righteous and had stumbled because she was evil, and they could never be saved because of how she was raising them. Yates then paraphrased Luke 17:2, saying, "It is better for someone to tie a millstone around their neck and cast them into a river than to stumble," Ferguson told jury.

She added that Yates did not believe she was mentally ill.

Prosecutors, who rested their case Wednesday, contend Yates knew her actions were wrong because she called 911 after the crime and later told a detective she killed her children because she was a bad mother and wanted to be punished. They also said she did it after her husband went to work and before her mother-in-law arrived.

Ferguson testified that Yates showed signs of paranoia when she reported hearing voices and said the media had put cameras in her cell, but prosecutors showed the jury pictures of Yates' cell that had a surveillance camera and intercom.

When she asked Yates if she was suicidal, Ferguson testified, Yates said, "I cannot destroy Satan; only the state can." Ferguson said Yates believed President Bush was still the Texas governor, and that Yates said that he would destroy Satan.

On Thursday, a former case worker testified that the day after the drownings, Yates asked for a razor to shave her head. She said "666" — the "Number of the Beast" in the Book of Revelation — was on her scalp, Corey Washington testified.

Washington said he stood to look at the back of Yates' head and noticed three marks that he was told were scabs where she had picked at her scalp.

"I kind of buckled a little bit," Washington said.

Prosecutors still plan to call Dr. Park Dietz, the psychiatrist whose testimony inadvertently caused Yates' conviction to be overturned. They said that he would testify during the trial's rebuttal phase, after the defense presents its case.

Dietz, also a consultant to the "Law & Order" television series, told jurors in Yates' first trial that one episode depicting a woman who drowned her kids in a bathtub — and was acquitted by reason of insanity — aired before the Yates children died. No such episode existed.

Yates, who turns 42 on Sunday, will be sentenced to life in prison if convicted. She is being tried in only three of the children's deaths, a common practice in cases involving multiple slayings.