2015/04/06

The Conversation April 2, 2015: Forensic evidence offers only probabilities, not guarantees that justice will be served

Scientific evidence and expert witness testimony are integral to criminal trials worldwide. Yet while we live in a scientific age of increasingly specialised expert knowledge, a growing reliance on forensic evidence is a double-edged sword.

There is no doubting that forensic science techniques provide near-miraculous abilities to detect, investigate and prosecute crime. But any powerful medicine can have strong side-effects, if administered in excessive dosages or to the wrong patients. Forensic scientific evidence has won for itself an aura of credibility that verges on infallibility. This leaves flawed expert evidence as a potent source of potential injustice.

Is forensic science evidence fit for justice? Science and technology constantly evolve; forensic tests become ever more discriminating, cheaper and easier to use, and more freely available to law enforcement. Courts and legislators must not be complacent if they are to keep pace with scientific innovation. Unfortunately austerity-blighted Britain may be storing up serious trouble for the future.

Forensics and miscarriages of justice

It shouldn’t surprise us that forensic science is associated with miscarriages of justice. All forms of judicial evidence are inherently fallible: witnesses are sometimes dissembling or forgetful, or sincere and credible yet wrong. Confessions may be false or made under duress. As reliance on scientific evidence grows so too will the number of miscarriages of justice that stem from forensic science. It’s also fair to say that injustice occurs when the scientific evidence and techniques available are not exploited to their maximum. Scientific evidence is in some areas peculiarly vulnerable to unreliability and misinterpretation. more