Forensic Science Evidence and Miscarriages of Justice

Abstract

Any fair and effective criminal justice system must ensure that evidence of guilt will be decisively more convincing than the defendant’s claim to innocence. This burden on the prosecution, to satisfy the judge or jury of proof beyond a reasonable doubt, promotes an acceptance in law (if not in the popular press) that “It is better that ten guilty persons escape than that one innocent suffer” (Blackstone, 1769: Vol. ivp.27). Despite such fundamental tenets, and despite even the sophistication of contemporary forensic science,the criminal process does still convict the innocent. While forensic science is acclaimed in the media, it has a blemished history in reality. Many infamous miscarriages of justice suffered from scientific evidence that was flawed, misrepresented, or suppressed (Walker and Starmer, 1999). “Scientific” methods of identifying criminal perpetrators have certainly advanced dramatically but are not infallible. In this chapter, we shall outline the meanings and prime causes of “miscarriage of justice,” providing examples of cases where forensic identification methods have been at the heart of miscarriages of justice. We then examine the mechanisms in England and Wales for remedying miscarriages of justice and assess their success.