The role of the expert witness and the opinion evidence that they present in
court has caused, and continues to cause, issues; experts often do not agree
and may hold widely differing opinions or may present their evidence in
ways which make it difficult for a jury to follow. More recently, the increase
in the use of DNA evidence to examine past cases has shown that experts can
be the cause of miscarriages of justice. It quickly becomes apparent that the
issues around the use of expert witnesses are global, but each criminal justice
system has differences that anyone attending court in this role needs to
understand prior to giving evidence. Despite this, the literature which exists
around the role of the expert is surprisingly limited in scope.