In 1913 W.M. marston noticed there were definitent changes in blood pressure with criminals.To than figure out they where lying which in turn started the process of the detector
In 1921 larson used marstons theories against 4,000 criminals, to see if it actually worked seeing if they would prove they did what ever they did.
In 1923 it was first used in the frye vs united states case.To find out frye was lying about what he did and was put in jail.
Since 1924 police have been using the lie detector for investigations.Against thousand of criminals so they wouldn't have to do more work like they did before the detector.
Leonarde Keeler in 1930 helped set up a crime labartory for it in the northwest a year before the fbi.To make improvements to the detector and so there would be a place to test it on people.
But the lie detector isn't always right, in 2003 gary ridgeway the green river killer passed the test where a innocent man failed. The man was put away for no reason and gary got away til he finally just convinced he did it.
pictures from sentences
frye vs united states case
imporntance and consequces
But lie detectors can be very wrong at times police could be locking up the wrong person because it didn't work right, it was bad for criminal organizations because they weren't able to lie and were put in for more time for lying
Wikipedia. Wikimedia Foundation, n.d. Web. 29 Sept. 2015.
"History of the Lie Detector or Polygraph Machine." About.com Inventors. About.com, n.d. Web. 29 Sept. 2015.