Words Left Unsaid: The Probative Value of Failure to Mention a Distinctive Feature

Witness descriptions of perpetrators sometimes leave out details. However, there are principled reasons to believe that witnesses should tend to mention distinctive physical features (e.g., tattoos, piercings, etc.) and that, therefore, failure to mention those features implies either that the witness did not get a good look or that those features were absent. Participants viewed mugshots from a database of a county jail in the U.S. and provided descriptions. For half of the participants, a follow up question was included asking if the participant noted any distinctive features. Results showed that failure to mention a distinctive feature was diagnostic of the feature’s absence and that this was especially true when a specific probe was asked. Implications for police practice are discussed.