This post is slightly late but relates to an interesting development in Singapore. In May 2014, the Singapore Court of Appeal issued interesting observations about witness body language (here). While those observations were made in the context of a civil case, they will be particularly relevant for criminal cases. Citing scientific studies on how nervousness is often misinterpreted as deceitfulness, the court held: “Put simply, therefore, the demeanour of a witness on the witness stand is not invariably a conclusive indicator of deception. ”
An insightful media report on this by Andy Ho may be found here.
Very interesting. “Hats off” to Singapore for officially recognizing this. Reading of body language is one of the underpinnings of the Reid Technique of interrogation used in the US. And of course, just as shown with the data from Singapore, their readings of body language are no more accurate than pure chance.