"Deception detection" experts—often former CIA agents—are used by banks and hedge funds to assess the honesty of CEOs. In his recent book, Broker, Trader, Lawyer, Spy, Eamon Javers shares some tricks of the trade:

1. Fidgeting
Aside from true sociopaths, people aren't natural liars, and saying one thing while thinking something else can actually cause physical discomfort. That's what causes people to squirm.

2. Weasel Words
Expected to, probably, basically, should be...
These kinds of qualifiers crop up when someone is trying to obscure doubts or worries.

3. Detour Phrases
Think, As I said before. Liars try to circumvent a direct answer by referencing past answers to different questions.

4. Complaints
Gripes like "How long am I going to be here?" are often used to derail a particular line of questioning.

5. Selective Memory
Phrases like to the best of my knowledge are evasive maneuvers, designed to get away from telling the truth or having to tell a bald-faced lie.