There are different ways to trip up liars. One is by analyzing facial expressions.
Several facial cues suggest that someone is faking an expression, among them:
• The muscle contractions on the left side of the face differ from those on the right side.
The expressions start and stop in a jerky manner.
• The person holds the expression for too long.
Eye movements also provide information. Someone looking downward may be sad, while someone looking down or away is more likely feel- ing shame, guilt or disgust.
Read more here. (Scroll down for the most interesting part - it has lots of photos.)
And here’s more on seeing and even hearing lies here. In the story, the reporter was asked to pick a number between 50 and 100. Then a law enforcement consultant read the numbers very rapidly and was able to pick out which one she had chosen - even though she didn’t say a word.