Child sex offenders given polygraph tests HERTFORDSHIRE, England, Dec. 31 (UPI) -- Britain is studying the use of lie-detector tests on child sex offenders to gauge if they warrant further investigation, officials said. In a trial being run by Hertfordshire police, 25 sex offenders deemed to be low risk were asked to take the tests, The Independent reported Saturday. Of the first 10 tested, police said six revealed behavior more serious than they were initially suspected of and were investigated in greater detail. Two others disclosed information they later refused to admit to in a formal interview. Results of the tests are not admissible in court as evidence. The trial is being overseen by Professor Don Grubin, a forensic psychology specialist at Newcastle University.