Andrea Yates, a Houston mother who systematically drowned her five children in the family bathtub, was found not guilty of murder Wednesday by reason of insanity.

The 42-year-old will be committed to a state mental hospital, with periodic hearings before a judge to determine whether she should be released.

If convicted of murder, she would have faced life in prison.

Defense attorneys never disputed that Yates killed her five children — 6-month-old Mary, 2-year-old Luke, 3-year-old Paul, 5-year-old John and 7-year-old Noah — by drowning them in a bathtub of their suburban Houston home in June 2001. They based their case, however, on a claim that she suffered from severe postpartum psychosis and, in a delusional state, believed Satan was inside her and was trying to save them from hell.

Another jury in 2002 had found Yates guilty of murder in the deaths of three of her children, but that verdict was overturned on appeal because of erroneous testimony. Prosecutors retried her on the same three counts of murder.

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Yates stared wide-eyed in court Wednesday as the verdict was read. She then bowed her head and wept quietly.

Outside the courtroom after the verdict, Yates' ex-husband, Rusty, referred to his former wife as a "loving mother who just fell to this disease" and called the verdict a "tremendous victory."

Rusty Yates, who divorced Andrea Yates and has since remarried, said the prosecution "just believed they had enough of the truth to proceed, they never made an effort to get the whole truth."

"It really disappointed me that the state spent ... probably a million-and-a-half dollars to get to really, what to me, was obvious from the beginning," he added, referring to her former wife as "psychotic."

Rusty Yates said he and his ex-wife are "good friends," and that he likely will visit her in prison later Wednesday. He said she was "very nervous" leading up to the verdict, and that she expected to be found guilty again. He thanked the jury for "rising above superficial facts," and said that in a mental institution she can have a "better quality of life for herself."

Rusty Yates also said he and and his former wife often reminisce about their children.

"Not very many people knew our children ... they were our lives, they were important to us," he said.

A capital murder conviction in Texas carries either life in prison or the death penalty. Prosecutors could not seek death during this retrial because the first trial's jurors sentenced her to life in prison, and authorities found no new evidence. Yates was charged in only three of the deaths, which is common in cases involving multiple killings.

Earlier in the day, jurors deliberating for a third day in the retrial asked to see a family photo and candid pictures of her five smiling youngsters. After about an hour of deliberations, they said they had reached a verdict. Attorneys were then called back to the courtroom.

The jury has been trying to determine if Yates was legally insane when she drowned her kids. Soon after arriving at the courthouse on Wednesday, it reviewed the state's definition of "insanity."

Prosecutors had maintained that Yates failed to meet the state's definition of insanity: That a severe mental illness prevents someone who is committing a crime from knowing that it is wrong.

In Yates' first murder trial, the jury deliberated about four hours before finding her guilty.

The jury had asked during deliberatioin to review the videotape of Yates' July 2001 evaluation by Dr. Phillip Resnick, a forensic psychiatrist who testified for the defense that she did not know killing the children was wrong because she was trying to save them from hell.

Resnick told jurors that Yates was in a delusional state and believed 6-month-old Mary, 2-year-old Luke, 3-year-old Paul, 5-year-old John and 7-year-old Noah would grow up to be criminals because she had ruined them.

Jurors later asked to review a November 2001 videotaped evaluation by Dr. Park Dietz, the state's expert witness whose testimony led an appeals court to overturn Yates' 2002 capital murder conviction last year.

Dietz, a forensic psychiatrist, testified in her first trial that an episode of the television series "Law & Order" depicted a woman who was acquitted by reason of insanity after drowning her children. But no such episode existed. State District Judge Belinda Hill barred attorneys in this trial from mentioning that issue.

On Tuesday, after jurors asked for the trial transcript involving defense attorney George Parnham's questioning of Dietz about the definition of obsessions, the judge brought the jury back into the courtroom.

The court reporter then read the brief transcript, in which Dietz said Yates "believed that Satan was at least present. She felt or sensed the presence." Dietz had testified that Yates' thoughts about harming her children were an obsession and a symptom of severe depression — not psychosis.

Earlier Tuesday, jurors reviewed the slide presentation of the state's key expert witness, Dr. Michael Welner, a forensic psychiatrist who evaluated Yates in May. He testified that she did not kill her children to save them from hell as she claims, but because she was overwhelmed and felt inadequate as a mother.

The Associated Press contributed to this report.