Life sentence for Texan mother who drowned her five children

Andrea Yates, the Texas mother convicted of capital murder for drowning her five children in a bathtub, was spared the death penalty yesterday. Instead, the jury opted to sentence her to life imprisonment, with no possibility of parole for 40 years.

The jury, which attracted controversy for its failure to find Mrs Yates guilty by reason of insanity, took 40 minutes to make up its mind after a day and a half of evidence in the penalty phase of the trial.

In their summing up, defence lawyers successfully argued that Mrs Yates, 37, posed no further danger to society so long as she had no more children – impossible while held in the Texas prison system. They also said her long history of psychotic breakdown and deep post-partum depression, as well as a lack of any criminal background, were mitigating circumstances.

The prosecution did not seek to argue that she posed any further danger, a legal prerequisite for imposing the death penalty, and indeed seemed unconcerned as to her fate. "Whatever you decide, the state will accept," the prosecutor Kaylynn Williford told the jury in her closing statement.

Throughout the trial, media commentators and mental health professionals accused the Houston district attorney's office of seeking the death penalty for tactical reasons – to ensure the toughest possible jury and maximise the chances of having Mrs Yates convicted on full criminal charges, despite her history of mental illness.

Controversy over the state's handling of the case lingered to the end, as it became clear that one piece of prosecution testimony had no basis. During the 17 days of testimony, the prosecution's chief expert witness, a psychiatrist called Park Dietz, said he had acted as consultant on an episode of the television show Law and Order, in which a mother drowns her children and then is acquitted on grounds of insanity. The lead prosecutor, Joseph Owmby, then insinuated that Mrs Yates – a fan of the show – might have hatched a plot for infanticide based on what she saw on TV.

By agreement between the two sides, however, it was revealed in court yesterday that no such episode of Law and Order had been produced, and Dr Dietz had not advised the show's producers on any such issue. The defence argued that the jury had been misled and urged the judge, unsuccessfully, to declare a mistrial. The issue might still arise on appeal.

The Yates conviction has appalled mental health professionals, who say if an insanity defence cannot work in her case – she was committed to hospital several times – it should be discarded as a legal concept.

A human rights group also filed a complaint with the Texas State Board of Medical Examiners yesterday, alleging that Mrs Yates' psychosis was created by poor medication and premature release from care.