Why don they use lie detector machines in murder cases where there is a fairly obvious suspect?
Simply becuase there is NO lie detectors. As a matter of fact it’s not even called lie detector, it’s called “polygraph”. The polygraph can’t detect if you lie or not, it only detects if you get nervous or not. But you can get nervous because you being falsely acused of a crime; so the machine can’t tell if you are scared, upset, sick or lying. Also many guilty people can pass the test. So the results are not reliable, that’s why it’s illegal in court. The police know the machine doesn’t work but they use it as a scare tactic to trick you into confessing. Police is even allowed to lie and tell you that you didn’t pass the test even if you did. EDIT By the way, I know that in TV shows they sell the machine as 100% foolproof but that’s only TV stuff and 100% fake.
