The New York Times reports, “Liars do not avert their eyes in an interview on average any more than people telling the truth do, researchers report; they do not fidget, sweat or slump in a chair any more often. They may produce distinct, fleeting changes in expression, experts say, but it is not clear yet how useful it is to analyze those. … No brain-imaging machine can reliably distinguish a doctored story from the truthful one … ditto for polygraphs…. One broad, straightforward principle has changed police work in Britain: seek information, not a confession. … “These interviews sound much more like a chat in a bar,” said Dr. Bull, who, with colleagues like Aldert Vrij at the University of Portsmouth, has pioneered much of the research in this area. “It’s a lot like the old ‘Columbo’ show, you know, where he pretends to be an idiot but he’s gathered a lot of evidence.”
Read more about how listening to people tell stories – including asking them to tell the story in reverse – helps police ferret out liars here.