The New Yorker addresses this issue again, how law enforcement uses half-baked scientific theories to convict, and sometimes execute, the innocent.

This particular article is about more than that, but it's a definite aspect. Note the following idiocy from someone who absolutely believes he's an expert.

Boudreau, a solidly built man who is now in his mid-fifties, told me that he had never relied on physical intimidation during interrogations. At the time of his encounter with Hood, Boudreau was an Army reservist. In 1990, during the Gulf War, he had deployed to Saudi Arabia; after the September 11th attacks, he had participated in the Ground Zero rescue effort. When he discussed interrogations with me, he spoke like a student of cognitive science. "It's all right-brain, left-brain," he said. "When someone is recalling something, they look left. But when they're creating an answer they look right." He claimed that people who spoke with their hands near their mouths were acting suspiciously, and theorized that "when someone's tapping their leg you can see that if they had full movement they would be running away."

Please read both links.