back to article Sex crime 'lie detector' pilot could prompt wider use

Paedophiles and other sex offenders on probation will face compulsory "lie detector" tests from next month, The Register has learned. The academic who will run the tests of controversial polygraph technology on sex offenders for the government believes a successful trial will lead to its use in other crimes. From late April, …


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  1. Anonymous Coward

    Trial by polygraph?

    Whats next, gutting goats and reading their entrails to find the location of Bin Laden?

    I'm a citizen, get me out of here!

  2. Anonymous Coward Silver badge
    Anonymous Coward


    Why don't you just put your suspect on one side of a balance and a goose on the other? Or toss dice? The evidentiary value would be about the same, and think how much money you'd save.

  3. Anonymous Coward
    Thumb Down

    Polygraphs are nowhere near reliable

    so I fail to see the benefit of this.

    What are they going to do about it if they say you're lying and you say you aren't?

    If the only "evidence" is the polygraph, they have no evidence at all.

  4. Steven
    Black Helicopters

    Bladerunner time?

    "A turtle is lying on its back in the desert. Do you right the turtle?"

    (Yes, it's horribly misquoted, but it I hear the word retirement in any of these press releases soon, I'm getting a grubby overcoat and a unicorn....)

  5. Francis Fish

    Are you now or have you ever been a Communist?

    McCarthite techno solution to not funding things properly. People with certain kinds of serious personality disorder can get past these with no problem, and a lot of them are probably the people you'll be questioning.

    Waste of time.

  6. John

    Unreliable ?

    I was under the impression the polygraph was pretty darned unreliable?

    Or am I mistaken ?

  7. Dave


    "We need to not outrun the evidence"

    What does that actually mean? Crims need to make sure that they can run faster than their victims?

    Sounds suspiciously like normal Gov decision making: "We need to be able to ignore all relevant evidance"

  8. Mark
    Thumb Down


    Isn't it a well known fact that these machines can give no absolutes, only a possible indication if the person is lying...

    By all accounts if you clench you arse while answering the control questions they are unable to get an accurate reading on the rest of the questions. Also if you are too shaken and nervous you will fail every question even though you are not lying....

    If they start depending on this technology to find out who has perpetrated crime prepare for millions of miscarriages of justice, and lots of people let out to carry on with thier lavish criminal lifestyles with no comeback.....

  9. John

    apparenlty I recall right..

    "There is little scientific evidence to support the reliability of polygraphs.[16][17] Despite claims of 90% - 95% reliability, critics charge that rather than a "test", the method amounts to an inherently unstandardizable interrogation technique whose accuracy cannot be established. A 1997 survey of 421 psychologists estimated the test's average accuracy at about 61%, a little better than chance."

    Taken from

  10. Anonymous Coward
    Anonymous Coward


    This is not a terribly good idea: if polygraphs work at all (which is a serious question in itself), they work best on people who are able to distinguish truth from lies, and who feel guilty or at least uncomfortable about lying. Paedophiles often don't fit into those categories.

    Polygraphs are rubbish. They're legal to use in the US but even private security firms deploy them incredibly rarely because they're so discredited. There was a very good article on them, and recent "innovations" in the New Yorker in 2007:

    This is, of course, completely typical of the government's approach: dredging up technology with a dodgy track record and whose application poses significant liberties questions, then using an undesirable group as guinea pigs (who's going to lose political points by being made to look as if they're "standing up for paedos"?) in a worthless trial before rolling it out to the wider population...

  11. John Imrie Silver badge
    Black Helicopters

    Polygraph tests

    And how to beet them.

    A polygraph test can not tell if you are lying. It shows how much you are sweating and how fast your heart is beating and, passably, several other factors.

    This is compared against a base line of responses from a set of 'neutral' questions given at the start of the test.

    So to beet the polygraph test all you have to do is make sure that your responses to the neutral questions match those of the questions the operator wants you to answer.

    The easiest way of doing this is to put something small and sharp in your shoe and press down on it when answering the 'neutral' questions. Then complain about being nervous and ask if this will affect the test.

  12. Anonymous Coward

    detect lies?

    but surely a polygraph is purely subterfuge to get people to admit their guilt - it has no ability to detect lies whatsoever - it may still work on people who dont understand this of course

  13. Anonymous Coward
    Anonymous Coward

    Yeah, Right!

    "Grubin added that given the vulnerability of polygraphs to faking, no decisions about the management of recently-released sex offenders would be made solely on the basis of their results."

    Ha. Given the blind faith in technology these days that won't last long before being "forgotten".

  14. ceedee

    Participate or else!

    "Grubin added that given the vulnerability of polygraphs to faking, no decisions about the management of recently-released sex offenders would be made solely on the basis of their results."

    But why should offenders, who've already been judged safe to release, have their licence revoked (meaning they get returned to prison) if they refuse to participate in the trial?

  15. Cameron Colley

    Why don't they just read their fucking tea leaves while they're at it?

    Since every scientific study I've seen seems to suggest that polygraphs are about as useful as torture for extracting the truth (read "not very").

    Why don't the government just hire remote viewers to follow the "peado's" about?

    Fucking morons.

  16. Anonymous Coward
    Anonymous Coward


    This, dispite there not being a shread of evidence that polygraphs represent a reliable test.

  17. Anonymous Coward
    Black Helicopters

    Blake's 7

    This polygraph stuff always reminds me of the "justice machine" in Blake's 7.

  18. Lottie

    Hmmmm How will this work then?

    "so Mr. P. Phile, have you had contact with children recently?"

    Paedophile thinks about certain type of "contact with children" and heart rate, sweat production etc all increase and register false positive?

  19. Anonymous Coward
    Thumb Down


    Why doesn't the Government just f&"k off, I've had enough of their Stalinist crap in the name of 'Terrorism' and 'Protection for Children'

    From a pissed off comrade who WILL get of his arse and vote at the next election!

  20. Anonymous Coward
    Anonymous Coward

    The right result guaranteed

    If the lie detector says true then thats a tick - unless there is long term follow up to check if the person was really telling the truth about that specific question, which I'd guess as v unlikely.

    If the lie detector says lie then thats a tick - unless the person being tested can prove they're telling the truth, and the chances of being able to do that will depend on the kind of questions asked, so likely to be minimal.

    If the person refuses to take the test then thats a tick as they're obviously guilty.

    Looks like it could be time to buy shares in lie detector manufacturers.

  21. Anonymous Coward
    Anonymous Coward

    wacki jacqui et al

    Lets see it used on wacki and her lying bast*rd colleagues/mates first.

  22. Andy

    A much more reliable method

    Just check if they weigh the same as a duck.

    (Well, someone had to say it...)

  23. Anonymous Coward
    Anonymous Coward

    QI Episode 3

    I reckon, the batty old cow watched QI, and saw the discussion about "the fruit machine" (a machine to determine homosexuality, which was used to sack civil servants who were claimed to be gay in order to 'prevent them being blackmailed' ....right.. to prevent them being blackmailed...).

    Anyway I reckon Jacqui saw that, as usual, she determines laws based on yesterdays news and TV, then decided that they'd have polygraph tests, then made this new rule based on a comedy program.

    Blunkett is long gone, he can hardly be blamed. Quite incredible that Brown doesn't get a grip on her.

  24. David Jewson

    Minister engages mouth before .........

    Why don't the government ever think these things through first?

    All that will happen is that paedophiles intending to offend again will move from these areas, probably to Brighton or Torquay where hoards of young children on holiday will be easy prey for their perversions.

    More of my taxes wasted on yet another government harebrained scheme. Dave.

  25. Anonymous Coward
    Black Helicopters

    Only useful as paperweigths

    A polygraph is only useful when used as a paper weight. As other commentards (TM) have noted here they are unreliable and it is the INTERPRETATION of the results against the question asked at that time which is the problem.

    A polygraph (as has been said) measures a set of biometrics. When you learn to control one or two of the more gross metrics _YOU_ can control the results.

    Many years ago, during boring days crossing the pond on one of Liz & Phil's Grey Funnel Liners (the big one with the flat roof) a group of bored young sailors (me included) tried duplicating an experiemnt that one of us had read about. The equipement was simple, some porn, some technical manuals and a heart rate monitor. The the victim was attached to the monitor and told a heart rate to achieve. He was shown porn when his heart rate was going towards, or at, the required rate. And Manuals when the rate was going away from the desire rate. 6 or 8 of used learned the trick in two days. I had fun later in hospital (following an MI) when I asked the doc what heart rate he wanted and then giving it to him. :)

    This skill was learned with little time and little resources, just to fill in some empty time. Someone with more motivation, and much better technology that we had, could easily learn to control heart and breathing rates and I doubt that sweating would be much more difficult. Then that person would really control the machine.

    And _HE_ wouldn't be a kiddie fiddler, the polygraph said so.

  26. Anonymous Coward
    Anonymous Coward

    Re: wacki jacqui et al

    You think that such consummate liars will be phased by a lie detector test?

  27. Anonymous Coward
    Anonymous Coward


    Are these the same "US authorities" that admit the thing's only any good against gullible fools?

  28. Anonymous Coward
    Anonymous Coward

    Polygraph evidence inadmissible in court

    Polygraphs are unreliable and hence inadmissible in court. If anyone receives any pseudo punishment as a result of a polygraph test, they should challenge it in court.

    UK Gilt Auction failed, if you don't understand how serious that is, it's the precursor to currency collapse. It means the government can no longer lend from real lenders and will have to lend from the Bank of England.

    You are now in a spiral, he has to borrow, but the only lender is the BOE, which in turn prints currency to cover it, which drives the pound down, which makes foreign government unwilling to lend, so future borrowing has to come from the BOE.....

    I say again, the EU should not bail out the UK, look at stuff like this Polygraph nonsense, look at the barring of MPs from the UK, look at the database crap. In no sense should this government be helped, Brown was not elected and it would be undemocratic to bail him out when British people want rid of him.

    You don't gain any favours by bailing out a leader that the country wants rid of.

  29. Philip Kroker

    What next Tarot cards?

    I remember reading an interview some time ago that was conducted with the guy who invented the polygraph, later in life. He said the the device did not work, he was ashamed he had made it and that he was trying to have it removed from the judiciary process. He also said that it was unlikely that it would be given up because the beurocracy was addicted to technology and silver bullet fixes and they would look like complete asses if they admitted it was unreliable (Imagine all the criminals they'd have to let go).

  30. Kevin

    Televised screenings

    The Jeremy Kyle fans would love it...

  31. John Smith Gold badge

    Some people might have trouble with this.

    "I just need to establish a baseline of your responses"


    "Your job title is Home Secretary?"


    "Your family name is Smith?"


    "Please turn over the piece of paper in front of you. Is that your home address?"

  32. Syd

    It doesn't need to be accurate...

    ... it just needs the testee (is that a word... the Firefox spell checker doesn't think so, but... ) to BELIEVE that it is accurate, so they think there is no point in lying.

    (Still sounds like a waste of money to me though, but...)

  33. Tony

    What about...

    ...bringing back phrenology? It is about as reliable.

  34. Schultz
    Thumb Up

    Sex questions

    Let me ask some question about your sex life.

    If you get nervous, we'll assume you lied to us.

    If you don't get nervous, you are a frikkin pervert, way too comfortable with your dirty mind!

  35. Anonymous Coward


    It has nothing to do with evidence, or proof, or justice, it's just another torch in the witch hunter generals army.

    "There my mob, the machine doth say he is a child buggerer, let us burn him!"

  36. Stevie Silver badge


    [Andy] Someone did, effectively. In comment #1.

  37. Anonymous Coward
    Anonymous Coward

    What are the odds?

    Home Office Polly - "Have you had any contact with children since your release?"

    Calculating Paedo - "Yes. Lots."

    Home Office Polly - "Er...the polygraph says he's lying."

    Calculating Paedo - "Ha, ha - now do you let me go or put me back inside? The Daily Tabloid will want to know."

    Home Office Polly - "We're bollixed! OK, sign this non-disclosure agreement and we'll give you ten grand."

    AC - wishing no possible association with either paedos or Home Office

  38. Luther Blissett

    Hyperreal evidence

    Polygraph evidence is no evidence at all in reality. But in hyperreality, due to its presence in so many films, the polygraph, simulacrum of evidence, is "in fact" the best evidence, as is well known, because it dispenses with all subjectivity, all emotions, all doubt, all humanity.

    The police, having had their hands slapped for profiling which justified fitting up saddos for various murders, have another toy to carry on the same game. But the police only "detect" anything in hyperreality. In reality, unless the criminals fall into the police's laps, the victim is often prosecuted to achieve the required strike rate. For in hyperreality, there are no crimes (at least, none that are the exclusive business of the police), only targets and detections.

  39. Anonymous Coward


    "Grubin added that given the vulnerability of polygraphs to faking, no decisions about the management of recently-released sex offenders would be made solely on the basis of their results."

    So why even bother, then?

    Mine's the alien with the probe in its pocket.

  40. kain preacher Silver badge

    @ac:12:54 GMT

    "They're legal to use in the US but even private security firms deploy them incredibly rarely because they're so discredited"

    Whoa there buddy. polygraph are not admissible in a court of law in the US. The only people that can be forced to take a poly are CIA, NSA ,FBI, or any one else whose job deals with national security. Then the poly is used for pre-employment questioning, and then for internal investigations to see weather you want to fire the guy or proceed with criminal charges .

  41. Anonymous Coward
    Thumb Down

    Creating problems in the first place...

    <daily mail answer>

    "Paedophiles and other sex offenders on probation" - why not just keep them in jail or have them executed? There problem solved...

    </daily mail answer>

    Polygraphs are passable if the person is able to control various stimulus whilst being questioned. Equally - someone with the correct levels of control can cause the system to fail on control questions. Whilst the above statement is harsh - perhaps tougher sentancing and better probation services when they are released would avoid the whole needing to control peoples lives like this. Also - I understand that things such as chemical castration etc. have had some effects on the most serious offenders.

  42. Anonymous Coward
    Anonymous Coward

    @ actually

    >'actually' wrote: This is, of course, completely typical of the government's approach: dredging up technology with a dodgy track record and whose application poses significant liberties questions, then using an undesirable group as guinea pigs (who's going to lose political points by being made to look as if they're "standing up for paedos"?) in a worthless trial before rolling it out to the wider population...<

    Spot-on. It's disgraceful. The Ministry of Justice ('MiniJust'..?) lives up to its chilling Orwellian moniker.

  43. Jason Bloomberg Silver badge

    Let's skip the horseshit

    Let's just turn the police into Judge Dredd clones and let them dispense justice as they feel fit *

    No worries about fuddy-duddy courtroom judges and limp-wristed liberal lawyers getting it wrong when we can rely on the plod on the beat to get it right. Seems reasonable as we all know not all coppers are bastards :-)

    * That also shuts up the debate about photography and all the other whinging about lost liberties. If you're dead you did something wrong. Tough shit, live ( or die ) with it. Other citizens take note.

  44. Ray
    Thumb Down

    ministry of justice.

    I was arguing against someone the other day who said we should 'just dump the paeds in the North Sea', and this latest proposal seems about as rational. I have no great love for them (!) but this latest rubbish HO initiative has nothing to do with the danger an individual represents to society or his or her rehabilitation.

    a: "The problem is there has been a lack of good data on its effectiveness"

    What he means is, there is a lack of data proving polygraphs to be effective. There's loads of data, it just proves the exact opposite of what he wants. Shame on you, prof. Sociology might have taught you stats but it is clear in this case that understanding doesn't necessarily follow from learning. That, or you know you're in the wrong.

    b: "Offenders who refuse to submit to the programme will violate their licence conditions and be sent back to prison"

    This sentence actually reads: "Submit to this ritual humiliation or we punish you some more, whether you did it or not."

    This latest scam is obviously the deformed brain-child of someone in Whitehall with no real ideas but quantifiable objectives to achieve for the minimum amount of cash, viz. more rehabilitated paeds, reduced prison crowding and a whole glut of Daily Mail sponsored votes in time for the next election.

    As long as the statistics go up or down by the right amount, you can have a winning career in government (and of course, if the stats don't go your way, you should have used a more ambiguous test).

    Mine's the one with the MiniLuv work request in the pocket.

  45. ElFatbob

    Re: Francis Fish

    Thanks - saved me the bother of typing that. Not forgetting that practiced liars can get around this technology and a large number of criminals are practiced liars.

  46. Trevor

    What happens when the liar gets through

    And what will happen when the screened fiddler gets away with lying for a while and then is discovered?

    Will the people running the test be held responsible for helping him continue his fiddling cause the test couldn't be wrong?

  47. Nigel

    Bring back the ducking stool?

    In the middle ages they had the right idea, except that they used it on "witches" instead of paedos. Submerge them in water for a few minutes and see if the drowned. If they did, they were innocent, and God had accepted them into heaven, so everyone left was happy. If they didn't, it was time to build a large bonfire on which to send them to hell, after which everyone left was happy.

    If you weren't sure, that's satire. Well, 90% satire. The other 10% of my brain is asking me to come up with a better suggestion for what to do about convicted paedophiles living amongst our children. Well, what should we do about a paedo who fails a polygraph test? Or come to that, one who passes it?

  48. Bod

    grubby overcoat and a unicorn

    "I'm getting a grubby overcoat and a unicorn"

    That's a sure way to get you on the sex offenders register ;)

    Mine's the grubby one with a paper unicorn in the pocket.

  49. Anonymous Coward
    Thumb Down

    so why bother?

    "The problem is there has been a lack of good data on its effectiveness,"

    given the vulnerability of polygraphs to faking...

    yes, that's quite the problem with them now, isn't it.

    anyway, the question is most properly phrased: When did you stop being a paedo? or

    when did you stop molesting sheep? or

    when did you realize you wanted to be wanked by the gubmint?

  50. This post has been deleted by its author


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