jueves, 13 de diciembre de 2012

Sex offenders lie detector

Yesterday's talking point dealt with lies. To round off the topic we are posting a Skynews video activity about a controversial gadget, the polygraph or lie detector.

Self-study activity:
Watch the video and answer the questions below.

1 How long has the programme been going on in the UK?
2 Name at least three aspects of the human body that lie detectors test?
3 What does 85% refer to in the report?
4 What method is generally used to monitor sex offenders when they are released from prison?
5 Why were some offenders more likely to admit a crime during the pilot programme?
6 What does six months refer to at the end of the clip?

In many countries the polygraph is a key law enforcement tool, and now in this country the government is convinced mandatory lie detector tests for sex offenders are the way ahead. The organizers of a two a half year pilots in the Midlands say that regular tests made a significant impact in preventing reoffending.
Successes of course are always invisible, but I have no doubt that a number of offences were prevented in the course of the pilot. On some occasions it's offenders who have been recalled to prison who said if they hadn't been recalled when they were, they would have reoffended.
Polygraph tests work by measuring blood pressure, heart rate, breathing and perspiration, which experts say display subtle changes when someone lies. Studies have shown they have around 85% accuracy rate. I agreed to take part in a simple test.

Choose one of the numbers, any one, and it’s number…
Number three.
Then quite simply I was asked to lie about that number when questioning.
Did you pick the number three?
Did you pick the number seven?

But however convincing I might have thought I was, there is, it seems, no fooling the machine.
…what you responded  at  various places through the chart, but where you responded particularly to the number it shows a big cardio response there and also you can see here your galvanic and scheme response.
The polygraph test will work in tandem with other safeguards like the sex offenders register which are designed to monitor the likes paedofiles and rapists on release from prison.
I think it’s going to be an important tool for probation officers in managing sex offenders on license in that second part of the sentence when they’ve been released from custody and are liable to recall prison if their behaviour gives any cause for concern.
The pilot programme found those tested were two to three times more likely to admit to offending behaviour knowing they’d be caught out anyway by the polygraph. Eventually it’s hoped all high risk sex offenders on licence will be tested every six months. Mark White Sky News.