Cot death or murder?

Angela Cannings says it was cot death. The jury said it was murder. But for women like her, the truth is more complex.

It was a moment to make your blood run cold. Angela Cannings, a mother who had been filmed cuddling her babies, who couldn't "work out what she had done in life" to deserve their deaths, sobbed in the dock last week as she was sentenced to life for their murder.

Even the trial judge, Mrs Justice Hallet, who described Cannings as someone who had cherished her babies, was concerned about the sentence imposed on her. She went on to describe the two mandatory life sentences – which, she said, she had no choice but to deliver – as an "injustice".

Cannings, 38, who maintains her innocence, claims that 18-week-old Matthew, who died in 1999, and seven-week-old Jason, who died in 1991, were victims of Sudden Infant Death Syndrome (Sids) or cot death, along with a third child, for whom charges were dropped, 13-week-old Gemma. The jury did not believe her, and during the trial there was no evidence given of another explanation, such as the possibility of Cannings' mind being disturbed. The case bears a striking resemblance to that of Sally Clark, the Cheshire solicitor who is serving life for the murder of her two babies, whom she, too, insists were victims of cot death.

So have there been miscarriages of justice? After Cannings' verdict, her solicitor, William Bache, compared her trial to the Salem witch hearings: he says they will appeal. Clark has already done so, on the basis that expert testimony at her trial suggesting that the chances of her suffering two cot deaths was one in 73 million was untrue. The expert involved, Professor Sir Roy Meadow, former president of the British Paediatric Association who also gave evidence in the Cannings' case, has since admitted that the figure was "misleading".

If the verdicts are correct, what drove these women to murder their own offspring? There is nothing new about a mother killing her babies. Babies under one year old are four times more likely than any other group to be murdered. And, for the past 64 years, women have been recognised as being particularly vulnerable in the period after birth: the crime of infanticide has been on the statute book only since 1938.

But these cases are much more complicated. Cannings and Clark could not be charged with infanticide because they both continue to deny they killed, even though they knew this would help get them shorter custodial sentences. According to the 1938 Act, mothers that kill a baby under one year old and who can be shown to be disturbed after childbirth can be charged with infanticide, but they must be willing to admit their guilt. Mrs Justice Hallett seemed to think Cannings must have been affected by the births. Although there had been no evidence given during the trial of Cannings' mental state, she said: "I have no doubt that for a woman like you to have committed these terrible acts there must have been something seriously wrong with you. It is no coincidence in my mind that you committed these acts in the weeks after their births."

According to the Foundation for the Study of Infant Death, 10 per cent of cot deaths that were at first thought to be natural have been caused by maltreatment, including negligence, extremely poor care or deliberate harm.

"A young baby is very vulnerable and easy to kill without leaving any signs," says Professor Rupert Risdon, histo-pathologist at Great Ormond Street Hospital, who has spent 20 years investigating sudden baby deaths. "People can't get their heads around the notion of a mother smothering her child, but if you live in the world I do you know that it goes on a lot." Professor Risdon was approached by the defence to help in the Cannings case but declined because he was "pretty sure she killed them". The evidence included post-mortem findings suggesting the boys had been smothered and evidence that both had suffered an "acute life-threatening episode" (gasping for breath and breathing heavily) before their deaths.

The case of Cannings highlights for some legal experts the need for more flexibility in sentencing. Her decision to deny the charge of murder rather than plead diminished responsibility meant that there were no psychiatric reports. Dame Helena Kennedy, QC, would like to see a change in sentencing. "It is 40 years since the end of the death penalty," she says, "and psychiatry has moved on. We know so much more about the human mind now. Justice has to be more flexible."

So what motivated Cannings? Is she in denial about her crime? "It's most unlikely," says Dr Maureen Marks, a consultant adult psychotherapist in perinatal services at the Maudsley psychiatric hospital in London. "Either she didn't do it or she's lying. She might have been trying to avoid punishment or she might not be able to cope with the shame."

What does Dr Marks think is the explanation for Cannings' crimes? Was she suffering from post-natal depression, which affects between 10 and 15 per cent of new mothers, or its rare and extreme cousin, puerperal psychosis? Or even Munchausen's Syndrome by Proxy, in which a parent harms his or her child to get attention? "It could be one of a hundred things," says Dr Marks. "It might be post-natal depression or it might be a personality disorder. Maybe she cannot bear her babies' needs. There's something about coping with young babies that taps into large and difficult feelings. A baby screaming can be unbearable for some people, especially when they've received bad parenting themselves. There is evidence that mothers who kill their children are more likely to come from a background of violence."

According to Dr Marks, Cannings can be helped, but she needs to first admit what she has done. One mother who did admit her culpability was Caroline Tait, 21, from Mere in Wiltshire. Last October she admitted smothering her three-month-old daughter when she would not stop crying. She was given a three-month probation order after evidence showed she was suffering from post-natal depression.

Dr Marks has more sympathy for the plight of Andrea Yates, the 36-year-old Texan who, suffering from post-natal depression, drowned all five of her children and then phoned the police. Under tough US jurisdiction, she was convicted of murder and sentenced to life imprisonment despite ample evidence that she was suffering from mental illness. "In Britain we have good laws for women killing babies," says Dr Marks. "Except when say they didn't do it."