Based on my own personal experience, I don't think current law enforcement officers' Polygraphs are necessarily harder than anybody elses. I just think that the examination is more biased toward police officers as we experience most of the "hot topics" discussed during the interview and examination. Most people aren't in contact with drug users and dealers on an almost daily basis, nor have they actually seen or held most of the common drugs that are out on the streets. But as Police Officers we do. How many of your friends that aren't Cops actually ever held a clip of crack viles, a fold of herion or one hundred nickel bags of marijuana? I don't know about your city or town, but where I work it's very common to come across these items. I feel that these encounters effect us subconsciously especially during stressful interrogations like a polygraph, thus resulting in either a false positive or inconclusive result. My personal experience with the polygraph resulted in 3 consecutive "inconclusive" results in the area of serious or major crimes, and I've been in Law Enforcement for over 8 years! Of course I've been around, observed and have even been a victim of serious crimes. But their machine doesn't lie, only cops do! (that's the attitude the examiners seem to take)  So don't feel like you are going through this polygraph nightmare all alone, there are many innocent victims of this witchcraft psuedoscience gone mad.