Four People Have Just Observed a Suspect Deny That She

Four people have just observed a suspect deny that she committed a theft. Which observer is most likely to detect whether the suspect is lying?

A) Andy, who has worked for the CIA
B) Frank, who is a rookie on the police force
C) Bobby, who is visiting the police station as part of a university assignment
D) Actually, none of the above observers have an edge in detecting lies.