LVMPD,

It's normal for a polygrapher to run three charts in the course of a polygraph interrogation. For more on the procedure, see Chapter 3 of The Lie Behind the Lie Detector. You'll see how being "totally truthful" actually increases your liklihood of failing these asinine "tests."

Regarding what to do next, while I have no specific information regarding Las Vegas Metro's procedures, I think the general guidance provided in Chapter 5 of The Lie Behind the Lie Detector should be a good starting point. Be sure to write a detailed memorandum for record of what happened during your polygraph interrogation (names, dates, times, etc.). And be sure to protest the polygrapher's conclusions in writing, and send it by certified, return receipt mail. If you can obtain copies of your polygraph charts and report, do so.

Have you spoken with your background investigator about this?

LVMPD,

My situation was very similar to yours, though not with a police department. It was with the CIA. I did marijuana once, and admitted to it on the drug question. They didn't believe I did it "just once" and polygraphed me. That polygraph interrogation was one of the worst 5 hours of my life. Hint: I failed it.

As for what you could do you, if you're going to (re)apply to a department that requires the polygraph, learn counter-measures. Don't have any qualms about it; everything they need to know about you they can learn in a background investigation. If the department requires CVSA, I don't know of any counter-measures for that..

Good luck, and remember you're not alone in having been screwed.