‘Few problems can pose a greater threat to free, democratic societies than that of wrongful conviction – the conviction of an innocent person.’ (Huff et al., 1986)

In a democracy, the presumption of innocence is of paramount importance. Although there is sometimes a natural desire among police officers to seek to prove cases well beyond a reasonable doubt, there is very real need to ensure that such desires do not lead to behaviours that are manifestly unfair and add unjustifiable strength to the prosecution case.’ (McKenzie, 1995)

‘Particularly alarming is the fact that police receive little or no training on lineups and photospreads, there are no rules or laws that prevent constructing and conducting line-ups and photospreads in ways that place an innocent suspect at risk, and courts are relatively insensitive to the ways these subtle variations in line-ups and photospreads have strong effects on the chances of mistaken identification.’ (Wells et al., 1999:72)

‘there are a large number of ways in which even well-intentioned witnesses can make mistakes which could result in the conviction of an innocent person.’ (Ainsworth, 2000a:174)

‘For the criminal justice system, the current findings suggest that police and courts should treat voice identification made by auditory-visual witnesses with caution.’ (Bull and Clifford, 1999)

Introduction

Very often, the identity of the perpetrator of a crime is not an issue or it can be readily established by the prosecution. In such cases, the primary concern of police investigators is to establish the necessary points of proof regarding the charges laid against the defendant.