The thin blue line-up: Comparing eyewitness performance by police and civilians

Police officers are often believed to provide more reliable testimony than civilian eyewitnesses. We reviewed the available empirical evidence for this belief. There is some evidence to suggest that police officers do indeed report more accurate details about witnessed events than civilians do, particularly concerning crime-relevant details. That research finding does not translate directly to practice, however, since an average difference between police and civilian witnesses does not mean that a particular police officer in a specific case should be believed over a particular civilian eyewitness. More importantly, police officers are no better than civilians at identifying a perpetrator from a line-up and may even be more likely to make a false identification. Because eyewitness misidentifications have far more severe consequences than misreported event details, expert witnesses in court should warn decision-makers that police officers are at least as likely as the average eyewitness to falsely identify an innocent person.