A critical analysis of medical opinion evidence in child homicide cases

There is no doubt that some parents or carers kill infants in their care. However, the prosecution of an individual for homicide ought to be based on reliable and accurate evidence of guilt. Recently, appellate courts have reviewed controversial infant homicide cases involving smothering or fatal inflicted head injury. These deaths are difficult to distinguish from accidental or natural deaths. Recurrent intra-family sudden death of infants and toddlers has, in a number of cases, been regarded as due to smothering. Infant deaths involving a triad of brain and eye injuries are usually attributed to shaking. Examination of medical literature on both types of death indicates there is rarely independent corroboration that suspicion of fatal abuse is accurate. Contentious appellate cases in common law jurisdictions of England and Wales, Australia, and Canada, and judicial and medical regulatory are discussed. Experts were not always impartial nor did they advise courts of significant limitations in infant death investigation. Medical and psychosocial evidence, both of uncertain reliability, were presented as independently corroborative of each other, which is misleading. Rigorous scientific or clinical methods were often absent. Admitting medical evidence, based on specialised training and experience, rather than considerations of its reliability and accuracy, has placed pressure on criminal trial safeguards (cross-examination, rebuttal experts and judicial directions) to reveal evidentiary problems to the jury. Wrongful convictions and dubious verdicts suggest the frailty and failure of safeguards, requiringchanges to how courts and prosecutors manage expert evidence in these cases. Incorporating psychological perspectives on expertise, the thesis proposes reliable expertise is difficult to acquire without feedback on accuracy. The thesis explains why expertise and specialised knowledge ought to be judged by drawing on psychological literature, as well as medical and legal discourse; why the pursuit of a prosecution ought to be seriously questioned when a case involves uncorroborated medical or psychosocial evidence, or there is significant disagreement between experts; and the problems inherent in relying on unconfirmed medical or psychosocial evidence to legitimise speculative medical opinion in the guise of science or authority is explained. The thesis concludes with suggestions for avoiding future wrongful convictions: greater medical focus on independent verification of the mechanical cause of death; and regulatory oversight of medical testimony and prosecutorial conduct, and reliance on a medical advisory mechanism in cases with serious issues with expert evidence