Shaken baby syndrome, also known as abusive head trauma or non-accidental head injury, remains a subject that divides opinion. The phenomenon is unique to infants and toddlers because of their anatomy; the weak and undeveloped neck muscles and disproportionately large head mean that upon shaking the brain bounces back and forth against the skull causing bruising, swelling and bleeding. Mainstream expert opinion has determined that the triad of symptoms with which infants present in such cases are indicative of, and consistent with, shaking. However, concern has developed amongst some experts that reliance upon the triad of symptoms to diagnose is problematic and can lead to miscarriages of justice as these symptoms can be consistent with other natural or accidental causes. Therefore, the question of whether shaken baby syndrome can be conclusively proven remains unanswered.
For a number of years convictions were based upon expert evidence of the ‘classic triad’ of symptoms. These included cerebral edema, subdural haematoma and retina haemorrhage. The presence of these three symptoms had been thought to be pathognomonic of shaken baby syndrome. This became known as the ‘unified hypothesis’ or Geddes theory. It was not until the case of Louise Woodward that experts began to accept that the classic triad of symptoms did not exclusively point to shaken baby syndrome.
In 2005 the Court of Appeal heard four separate appeals concerning the doubts that now existed amongst the scientific community about this evidence. It became clear that the Geddes hypothesis could no longer be regarded as credible. Dr. Geddes accepted herself under cross examination that her hypothesis could no longer be regarded as conclusive. In the case of Harris  EWCA Crim 1980 the Court of Appeal held that the classic triad should no longer ‘automatically or necessarily’ lead to the conclusion that an infant had been shaken. This case concerned the death of Lorraine Harris’ four month old son. The evidence was solely based upon the classic triad. There was no other evidence of abuse, neglect or rough handling. The new evidence, found the Court of Appeal, cast doubt upon the significance of the subdural haemorrhages that were found. It was clearly powerful evidence of shaking but not alone a diagnosis of shaking. Therefore, the conviction was quashed. This finding lead to the review of of shaken baby cases by the Attorney General Lord Goldsmiths which led to new guidance from CPS. Now it is clear that to prove that a baby suffered an injury consequent upon being shaken the Crown will usually require the triad of injuries in addition to some other supporting evidence.
To gain a conviction for murder the Crown would have to prove that there was an intention to cause grievous bodily harm. Attention should be given to the minimal amount of force required to injure and infant. Modern expert opinions accepts that the level of force required is an unknown. Tests on live humans cannot be carried out and all other methods of conducting researching, such as animal research, are not fully applicant to human infants. Therefore, this cannot be ascertained. There is an inference that if everyday accidents could cause these consequences then deaths from abusive trauma would be quite common instead of quite rare but it is no more than that. An inference alone is insufficient to prove an intention to cause grievous bodily harm. The case of Rock  Cr App R 5 was considered with Harris. The triad did not stand alone in this case. There was no dispute that Raymond Rock had shaken his partner’s thirteen month old daughter or that she had suffered an impact to the back of her head. However, an intention to cause grievous bodily harm could not be shown on the evidence and so his murder conviction was quashed in favour of manslaughter.
Further, even if these hurdles can be overcome the Crown still face the difficulty of proving who was responsible for the shaking. Hitherto a view had developed that the person last with the infant at the time of death was responsible but the research of Professor Tuerkheimer in the Washing University Law Review suggested that children suffering fatal head injuries may be lucid for more than 72 hours before death. This will make it difficult to pinpoint the time of injury and the identity of the perpetrator.
Use of the triad of encephalopathy, subdural haemorrhages and retinal haemorrhages as an indicator of head injury has stood the test of time and is not discredited by the case of Harris but, alone, it is insufficient. The Crown has a duty to protect vulnerable infants from care givers who fail to control their temper and it must continue to do so. However, there are real challenges that can, and should, be made both to the scientific evidence and the inferences that the Crown pray in aid to satisfy an indictment alleging murder or GBH.