FBI and law enforcement authorities' application of the sample-expression method is disputed by scientists.
A study published on October 14, 2020, in the Journal of Investigative Psychology and Offender Profiling by researchers in collaboration with Portsmouth University has raised concerns about the Truthful Statement lie detection method. This technique, currently used by both the FBI and British police, has been a crucial part of criminal investigations. However, detecting lies can be challenging due to the subtle differences between fabricated and genuine statements.
The Truthful Statement method, while showing promise, is not yet ready for practical use, according to the study. Cody Porter, a senior lecturer in Psychology and Criminal Behavior at Portsmouth University, warns that applying the Truthful Statement method is risky because it encourages both truth-tellers and liars to elaborate, making it difficult to distinguish between the two.
The method assumes that longer and more detailed statements contain more cues against deceit compared to shorter statements. However, the analysis argues against the use of the Truthful Statement method in criminal investigations. Porter suggests that practical applications of the Truthful Statement method should be re-evaluated.
The analysis also addresses the Example Expression method, which lacks a theoretical foundation and can affect memory performance. It can make liars' statements seem more convincing or encourage truth-tellers to produce false information. The analysis does not specify which interrogation techniques are part of the Example Expression method.
The goal is to reduce the similarity of verbal behavior between liars and truth-tellers in interrogations. Instead, researchers urge that investigators should develop tools that encourage liars and truth-tellers to adopt different verbal strategies. Porter advises that the application of the Truthful Statement method should be immediately reviewed, and the Example Expression method should not be used by police officers or interrogators.
The study concludes that the Truthful Statement method may actually hinder justice due to its potential to help liars tell better lies. Despite the concerns raised, further research is needed to develop more reliable methods for lie detection in criminal investigations.
