So i've got an upcoming polygraph, and I'm nervous. I can answer truthfully to every single question, except one: theft. Nothing big, but theft none the less. 

Should I try to lie, or should I fess up? I really want the fire department job, am i risking it more lying, or telling the truth? There is absolutely nothing on my record to substantiate any theft, no one knows about it besides myself and 1 friend, so would it be best to lie since there is nothing to prove I actually did it?

Is a question on theft a control question, where they expect everyone to have stolen something in the past?

MontBell,

Your theft may or may not be disqualifying, depending on how serious the fire department considers it.

Pre-employment polygraph examinations often include a probable-lie "control" question about theft. For example, the DoDPI Law Enforcement Pre-Employment Test may include the probable-lie "control" question, "Prior to ____, did you ever cheat anyone out of anything?" But some exams also include a relevant question about theft. For example, the Los Angeles Police Department's pre-employment polygraph examination includes the relevant question, "Have you stolen more than four hundred dollars in cash or property from an employer?"

As a general rule, it is never in an applicant's personal interest to volunteer negative information that would not be discovered in the course of a background investigation. However, those seeking positions of public trust have an ethical obligation to answer relevant questions truthfully. The fact that public agencies are themselves using a fraudulent procedure such as polygraphy that depends on the operator lying to and otherwise deceiving the applicant (see Chapter 3 of The Lie Behind the Lie Detector) muddies the ethical waters.