If the face fits replicate it in police line ups

Witnesses have a better chance of picking the perpetrator in a police line up if any facial distinctive features are replicated across all the suspects.

This is one of the findings of research by Associate Professor Kimberley Wade and colleagues from the University of Warwick who presented their research at the British Psychological Society's Annual Conference in Glasgow.

Approximately a third of all identification parades conducted in the UK involve a suspect who is prone to standing out because he or she has some sort of distinctive facial feature (e.g. tattoos, scars, bruising, moles).

Research has shown that mistaken identifications are more likely to occur when a suspect stands out in an identification parade. To counter this, police developed solutions in which they either edit the image replicating the feature across all line up members or they digitally conceal the distinctive feature with a patch that all members of the line up wear.

Building on previous research published in Psychological Science in 2009, this study tested another standard police technique of pixelating the distinctive area on the suspects face and pixelating the same area on all the other line up members.

95 participants looked at photos of real prisoners of which a small proportion had a distinctive feature digitally added to their face (i.e. tattoo, scar, mole, facial hair). The participants then attempted to identify the previously seen faces with distinctive features in a series of lineups.

The results showed that the pixelating images led to fewer correct identifications than either removal or replicating the feature.

Associate Professor Wade explained: "Currently there is no standard police procedure for dealing with suspects with distinctive features, even though this occurs in approx a third of line ups. Based on our previous research and this new study we would recommend the replicating method for obtaining optimum results from their witnesses."