"This is a subtle sign of fear that's only expressed in the eyes," says Matsumoto.
Matsumoto dissects O.J. Simpson's reactions to questions at a deposition when he was charged and later acquitted of murdering his wife. This psychologist teaches something called "micro expressions."
"Well, micro expressions are a particular type of facial expressions of an emotion that goes on and off a face really, really quickly and these are signs of emotions that are concealed," says Matsumoto.
To put it bluntly it is how to spot lying. However, the professor makes it clear micro expressions are just one of many clues that someone is untruthful.
"When you see things like micro expressions, the best thing is generally not to make a conclusion that the person is lying, but to conclude instead that there's more to the story than is being told," says Matsumoto.
Simpson is shown a picture which prosecutors say, shows him wearing Bruno Magli shoes, the same type which left bloody prints at the murder scene. Matsumoto points out a subtle expression in his eyes, a sign which expresses fear.
"So at this point, we know we got him. We know we've got something!" says Matsumoto.
Hans Reiser is the computer entrepreneur who was convicted of killing his wife Nina two years ago. Reiser did an interview with ABC News when he denied murdering her and hiding her body.
Reiser was asked "Do you think Nina is alive or do you think she's dead?" Matsumoto points out before Reiser responds he starts to have this sign of distress and a little bit of fear.
Reiser responds, "I think I'm the person who doesn't know."
"And now [his eyebrows are] raised up here... and the upper eyelids are raised. That's a low level expression of fear," says Matsumoto.
Matsumoto looks for verbal and non-verbal inconsistencies.
"So if I said to you, 'I really liked that,' by these words, I really like that, but my head is going 'No, no, no.' That would be a little inconsistency," says Matsumoto.
He also says shrugs of the shoulder generally mean "I don't know."
"When we say 'I don't know?' We go like this. We do it with our shoulder or sometimes or sometimes we do it with our hands," says Matsumoto.
Matsumoto says John Edwards' shoulder shrugs and head shakes were dead giveaways he was lying about his affair with a campaign worker. He says Edwards was shrugging his shoulders as he was saying "I've been in love with the same woman for 30 plus years," and starts to shake his head no a bit as Edwards said, "As anyone who's been around us knows, she's an extraordinary human being. I've been in love with this woman for 35 years."
Cops and lawyers are among Matsumoto's eager students. Attorney Tom Losavio is one of them.
"To evaluate whether or not someone is telling the truth, it could be your own client or your adversary, is a very valuable tool to have at your disposal," says Losavio.
A word of warning if you ever meet Matsumoto in a poker game -- do not even think of bluffing.