Determining how UK policing should construct identification parades

:Using diagnostic-feature-detection theory to maximise eyewitness identification accuracy

Identification parades are routinely administered by police forces globally to determine whether a witness identifies the police suspect as the perpetrator of a crime. During a parade, a witness views images of the suspect and others who resemble the suspect, called fillers. Worldwide, legal guidance on constructing parades uses the same central principle-the fillers should be plausible alternatives so that the parade is fair to the suspect (e.g., UK Police and Criminal Evidence Act 1984, Code D, 2017). Yet, even when constructing legally 'fair' parades, fillers can vary in similarity to the suspect. Currently, there is no evidence-based direction for identification officers on optimal filler similarity.

The research aims to determine how identification officers in the UK and internationally should select fillers, so that the parade is fair to the suspect (i.e., the suspect does not unduly stand out from the fillers), and maximises witness accuracy. It will do this by testing the newest psychological theory that makes predictions about the effect of filler similarity on witness accuracy-the diagnostic-feature-detection theory (Wixted & Mickes, 2014)-and by collaborating with the National VIPER Bureau, the UK's leading video identification service owned and managed by The Office of the Police and Crime Commissioner for West Yorkshire.

The project incorporates expert input from VIPER and their subscribers (police forces) to test real-world procedures in experiments and collect real-world data on parade similarity. The research will answer important theoretical and practical questions, and has been co-developed with the Director of VIPER, Mr Wayne Collins.