Yes, indeed. But thankfully the polygraph finds is best use in Post-Conviction Sex Offender cases which prevents these criminals roaming your streets and claiming more victims.
Sadly in the past 100 years the polygraph has been used by a lot of incompetent police officers who had no idea what they are doing with it and it owes it's bad renomee to them.
And how does it do that?
In the States every sex offender on probation has to take a polygraph test regarding whether or not they had similar sex acts/offenses similar to their crimes. If they fail the test, they go back to prison.