Person connected to lie detector
Media playback is unsupported on your device

Police trial lie detectors on sex offender suspects

Police have begun using lie detector tests on suspected sex offenders in a trial which could be widened.

Hertfordshire Police said it had been using polygraphs, which monitor heart rate, brain activity, sweating and blood pressure, during questioning.

The trial involved tests on 25 "low-level" suspects ahead of any charges being brought, the force said.

Sarah Campbell reports.

  • 31 Dec 2011
  • From the section UK