Obtaining information from people is crucial to an effective investigation. Once we obtain a statement or information from an individual, we must make the effort to verify the facts they provided. This is an important step, especially when someone confesses to a crime to ensure that the confession is true and reliable, but also with victims and witnesses, because they too can lie or simply be wrong. There is some interesting new research by Galit Nahari, Aldert Vrij and Ronald Fisher that indicates letting the individual know that you will be verifying their information they provide, before they provide a statement, can improve your ability to distinguish between a truthful account and a fabricated account. One of the reasons is that truthful people will try to provide verifiable details in their account whereas deceptive people may provide details, but often they are not verifiable by investigators. By telling the individual up front, this seemed to encourage truth-tellers to provide even more verifiable details whereas it had the opposite effect with deceptive individuals, thus creating an even a wider disparity within the language between truthful and deceptive people. Personally, I think there may be additional psychological benefits between truthful and deceptive people with this approach as well. Truthful people will perceive this as the investigator being professional and very thorough, which should reduce the anxiety of that truthful individual and increase trust, which will have a calming effect on them. This will have the opposite effect on a deceptive person since the last thing they want is someone who is very thorough scouring over their statement, and thus will likely increase their anxiety and cognitive load as well.
If you are a member of The Interview and Interrogation Group, click the following link and download the research article (The Verifiability Approach to Detecting Deception) for review and further discussion!