If a lie detector is inadmissible in court, then why are cops still allowed to use it?


Since the cops believe that everyone they suspect is automatically guilty,doesn't that stupid little machine pretty much close the book? Innocent until proven guilty or guilty because the polygraph says so and cops are just following protocol? Only a week disappeared of the Bush era...maybe things will change.
Best Answer:
They are allowed to use them for investigative purposes, not as admissible evidence in court. For instance, if you be asked in a LD test, "Did you kill that person", you answer "No" but the theory test shows you lied, they cannot use that in court but will definitely use it to further their investigation. The next quiz may be, "Did you dispose of the body by burying it?. You say "No", but the test says you did. The subsequent question could be, "Did you bury the body in your garden?", you say no, but the trial says you lied. How long do you think it would be before at hand is a bunch of police with a warrant and shovels behind your house? They would not be able to use the trial to prove anything, but what they found as a result of the test is admissible. The fact that the body was found buried contained by your garden would be considered circumstantial evidence. The test results are not used, but evidence gained as a result of the examination are definitely used. .
They cannot use them unless you give them your consent to do so. I recommend that no one ever get one.