Expert evidence and uncertainty in English infanticide trials, c. 1725-1945

At least since the eighteenth century, expert witnesses in English criminal trials have faced pressures to deliver their evidence in sufficiently certain terms. In some cases, however, experts provided lawyers, judges and juries with reasons for uncertainty and thereby introduced a degree of flexibility and discretion into the criminal law. The uncertainty in infanticide cases hardly ever stemmed from expert disagreement; rather, experts exerted ‘rectitude’ in refusing to say more than their knowledge warranted. This chapter focuses on two crucial periods in the development of infanticide law to further develop this argument on experts’ uncertainty. The first is the clarification in the 1830s of what it meant for a baby to be ‘born alive’. In a series of cases that served as legal precedents, the judges responded to medical uncertainty by formulating a legal question which in most cases made certainty on the expert’s part impossible. The second is in the years immediately before and after the Infanticide Act 1922. Even though this Act made the consequences of medical certainty and uncertainty much less dramatic, the same uncertainties continued to play a significant role in response to infanticide. In both episodes we can see the part that law plays in creating and using uncertainty in expert evidence. This refines and reinforces Dixon’s argument regarding the extent of the court’s receptivity to medical uncertainty and the scope it created for the jury to take into consideration social and economic factors, which in turn, allowed them to reach a merciful verdict.