It is a case that haunts Dr Waney Squier and one any parent will find deeply distressing.
Eleven years ago, Lorraine Harris stood trial at Nottingham Crown Court charged with manslaughter. Although described as a woman of good character and a careful and caring mother, she was accused of shaking her four-month-old baby Patrick to death two years earlier.
Neuropathologist Dr Squier wrote a report for the prosecution saying that the child was the victim of shaken baby syndrome (SBS).
About 250 SBS cases go to court each year. Expert witnesses play a pivotal role in trials. Babies often do not have any symptoms other than bleeding to the head and eyes so, unlike most criminal cases, the opinion of the pathologist may be the only evidence to consider.
However, some convictions are controversial. The problem has been that there is no single agreed definition of SBS. Instead, for the past 30 years, the findings of a U.S. radiologist, John Caffey, have been used in courts.
These findings centre on three signs – swelling of the brain, bleeding between the skull and the brain, and bleeding in the retina – known collectively as the triad. If they are present then a conviction is likely.
But Dr Squier is one of a growing number of doctors who believe that relying on the triad alone is no longer enough.
‘Over the past ten years so much more has been discovered about how a baby’s brain develops in its first year and these developments have seriously undermined SBS,’ she explains.
‘We now know, for example, that almost half of babies have a triad at birth, which can be caused by different factors.
‘In the past four years there have been several discoveries about the dura, the membrane covering the brain. It was thought that it was there to protect the brain from shock, but we now know it also has the very important function of controlling blood flow out of the brain.
‘At birth the dura has huge blood channels that can leak – and not always as a result of trauma. They do, however, disappear during the child’s second year of life.
‘These findings are so significant that I now believe that half or even more of those who have been brought to trial in the past for SBS have been wrongly convicted.
'I am also convinced we can virtually exclude shaking as a cause of death in babies unless, as well as bleeding in the brain, we have additional evidence of trauma, such as serious damage to the neck.
‘When a baby is shaken, the head will flop back and forth and the neck becomes the weak point. In other words, if you shake a baby so hard that it dies, it is the neck that is going to show the damage, not the brain.’
Unknown territory: Doctors are still learning how a baby's brain develops - and discoveries in just
he last ten years have 'seriously undermined SBS' according to Dr Squier
Although her view is gathering momentum worldwide, it has ignited an increasingly toxic argument between doctors, lawyers and police.
‘Some pathologists want to remain in an unchallenging comfort zone of an outdated theory,’ Dr Squier explains.
‘Some judges don’t like the fact that new scientific discoveries make convictions more complex, and the police don’t like them because it can prevent them from getting the convictions they want.
I think the police are so put-out that they are trying to ban me from court. It’s why I would like Justice Secretary Kenneth Clarke to set up an inquiry into the methods police have used to deter expert witnesses who challenge old mainstream beliefs.
'This raises serious concerns that one side of the argument is not being heard and means there cannot be a fair trial.
* 'Shaken Baby Syndrome' Probe Urges Injustice Cases Review
Chris Bentley, Attorney General, Government of Ontario
* Shaken Baby Syndrome Controversy Turns Toxic
BBC File on 4
* More USA Doctors Questioning 'Shaken-Baby Syndrome'
* Shaken Baby Syndrome Story & Metropolitan Police Witness Interference
Lisa Blakemore Brown, Psychologist
* Metropolitan Police Accused Of Trying To Campaign Against Shaken Baby Witnesses
Andrew Hosken, BBC Radio 4 Today Programme
* The Consensus Report
Family Law Reform