I thought I would share my experience from some years ago. I was absolutely dreading the polygraph. I was hoping they would forget about me when the time came. Unfortunately for them I found this site and it's contents.
I have been gainfully employed for the better part of six years at this point. They weren't able to stump me on any of the three polys I took. For those of you reading, I would share this info with your friends and family applying to and LE job. The process was tough, but I ended up not being accused of anything I didn't do.
A bit off topic. One of my former co-workers who was a total asshole to everyone, applied to different dept. He had to take another poly and made a whole bunch of admissions to things he didn't think were a big deal. Well the dept in question did, and reported him to Internal Affairs. :D IA fired his dumbass from his current job, and now he'll never work in Law Enforcement again.
Do your homework kids!