ABSTRACT
This chapter discusses the problem in some depth and shows why the interpretation, and hence the presentation, of DNA evidence matters, and examines the methods which have been proposed for explaining the significance of such evidence to juries. It focuses on the use of DNA evidence in criminal litigation; many of the arguments are applicable to any probabilistic evidence used in the courts. DNA merely offers a clear point of focus for the discussion, and it is that the problem is presently most acute. Adams is a striking example of how apparently damning DNA evidence, when combined with a number of pieces of exculpatory evidence, can produce relatively modest posterior odds on guilt. Adams was very much a test case for the legal system. Although cases like it will probably always be rare, the inception of the DNA database means that we will be seeing more of them.
