The phenomenology of carryover effects between show-up and line-up identification

This study explored carryover effects from show-ups to subsequent line-up identifications using a novel paradigm in which participants rendered multiple identification judgements. A total of 160 participants studied a series of faces and subsequently viewed a series of target-absent and target-present show-ups. Following a retention interval, participants then made identification judgements from a series of target-absent and target-present line-ups. Remember-Know-Guess judgements were collected to assess the phenomenological basis of carryover effects in face identification. Our results indicated clear carryover effects from show-ups to line-ups, such that repeated exposure to a face increased the likelihood that it would later be identified, regardless of whether or not it had been presented at the time of study. The phenomenological basis for these carryover effects is discussed, as are the implications of these findings for police conduct of multiple eyewitness identification procedures.