With a blood pressure cuff pumped tight around my arm, straps around my chest monitoring my breathing, and sensors on my fingers to pick up any traces of sweat, veteran polygraph test examiner Don Cargill says he can easily spot the signs I’ve told him a fib.
I’ve denied writing the number three on the piece of paper placed underneath my chair, in a simple exercise designed to show how my body reacts to lying. Even with nothing to lose, it’s an uncomfortable experience.
But while commonly associated with daytime television programmes like The Jeremy Kyle Show, the use of lie detectors is expanding within the criminal justice system.
And the answers people give could help determine whether or not they can see their children – or even land them back in jail.
Image: Lie detector tests featured regularly on The Jeremy Kyle Show. Pic: ITV
In an office above a branch of Carpetright in west London, Mr Cargill carries out private polygraph tests. His clients have included foreign politicians accused of bribery, bodybuilders who want to prove they haven’t taken performance-enhancing drugs, and people accused of stealing from their family or being unfaithful to a spouse.
More and more are trying to cheat the polygraph using instructions found online, he says. “There’s a lot of techniques they do but we spot 90% of them or more.”
I’m asked to jump up and down and open my mouth before my test. Some people have pressed drawing pins into the bottom of their shoes, or even superglued tacks in their mouths, to create a pain response in their brain to distort the chart, Mr Cargill says.
He asks for identification to make sure a stand-in hasn’t been sent and carries out other simple tests to spot signs of sleep deprivation or illegal drug use.
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A camera is trained on the subject’s eyes to make sure they don’t cross them or “zone out”, while a seat pad is in place to catch out anyone clenching their bottom.
All of these methods have been used to try to cheat the test, Mr Cargill says.
Image: Sky’s Henry Vaughan takes a lie detector test
Can lie detectors be cheated?
It is possible to beat the polygraph, says Newcastle University Emeritus Professor Don Grubin, but it takes a lot of practice with the equipment and examiners are trained to spot the signs of anyone trying to trick the test.
Double child killer Colin Pitchfork – who was jailed for life after raping and strangling 15-year-olds Lynda Mann and Dawn Ashworth in Leicestershire in 1983 and 1986 – was recalled to prison in 2021 partly due to concerns he was using breathing techniques in a bid to beat the lie detector.
The Home Office says the polygraph records physiological changes in a person, quoting research from the American Polygraph Association which found deception is accurately detected in 80 to 90% of cases.
Since 2014, probation services have carried out more than 8,800 polygraph tests, while police have conducted more than 4,600, says Prof Grubin, who explains around 60 to 70% result in disclosures – where someone reveals relevant information.
His company, Behavioural Measures UK, has trained and supervised dozens of police and parole polygraph test examiners over the past decade, and like other experts in the field, he doesn’t like the term lie detectors.
The technology detects the “cognitive process” (or the brain working harder) when someone tells a lie, he explains.
Image: The results of a polygraph test
The “real skill lies in the experience of the examiner”, says Mr Cargill, the chief executive of VAST Screening Technologies Ltd and the chairman of the British and European Polygraph Association.
“Nervous reactions are completely different from people telling lies,” he says. “Your heart rate physically increases because you’re triggering the autonomic nervous system, which triggers a fight, flight or freeze response. You want to run away.”
But critics, including University of Northumbria researchers Dr Marion Oswald, a professor of law, and associate professor Dr Kyriakos Kotsoglou, say much of the research is carried out by the industry itself and the accuracy can’t be tested in a real-life situation – because it is impossible to verify if someone has told a lie.
They say it is an intrusive “interrogation” technique used to illicit confessions, arguing the polygraph device itself is unnecessary and could be swapped for putting someone’s hand on a photocopying machine – a method apparently used by Detroit police and immortalised in cult American crime drama The Wire.
“If you can convince the subject that she or he is being monitored for lies and they believe it, then she or he will disclose more information,” says Dr Kotsoglou.
How are lie detectors used?
The results can’t be used as evidence in criminal courts but mandatory lie detector tests have been used as a licence condition for sex offenders since 2014, then rolled out to convicted terrorists in 2021 in the wake of the Fishmongers’ Hall attack.
They are also used by police and the security services to monitor the small number of terror suspects made subject to Terrorism Prevention and Investigation Measures (Tpims).
There is currently a three-year trial for their use on domestic abuse offenders, while the new Criminal Justice Bill proposes to extend this to convicted murderers who pose a risk of committing a relevant sexual offence on release.
The tests provide “invaluable information we would otherwise not have had about offenders’ behaviour which helps us to better protect the public”, the Ministry of Justice says.
The Metropolitan Police is looking into using lie detection technology to vet new recruits or root out corrupt officers following a string of damaging scandals, including the cases of Sarah Everard’s murderer Wayne Couzens and serial rapist David Carrick.
Image: David Carrick and Wayne Couzens
But “this is still at an early research stage” and there are no imminent plans to use the technology in this way, the force says.
Others are turning to lie detectors to try to prove their innocence.
Kevin Duffy, 70, passed a polygraph test after he was convicted of sexually assaulting a child, but the results weren’t taken into account by the judge who jailed him for more than nine years.
His son Ryan Duffy, 44, says: “If there’s something that can be used when it’s one person’s word against another’s that can highlight some kind of evidence, why can’t it be used?
“If they are prepared to look at it after conviction for single case issues such as, ‘are you using public transport, hanging around schools’, and relying on data for probation services, then why can’t you use it beforehand?”
Image: Kevin Duffy took a polygraph test to try to prove his innocence. Pic: Ryan Duffy
People can’t be sent back to prison for failing a test, but they can face further sanctions, such as stricter licence conditions, and they can be recalled for making disclosures that reveal they have breached licence conditions or indicate their risk has increased.
The information gathered can be shared with police to carry out further investigations, which could lead to charges, while those found trying to trick the polygraph can also be recalled to prison.
A government report last year revealed four convicted terrorists were sent back to jail as a result of lie detector tests – three were recalled after disclosing “risk-related information”, while the fourth didn’t comply with their polygraph licence condition.
Image: Sensors pick up any traces of sweat during the polygraph test
An increasing number of police forces are using the polygraph, which is seen as a useful tool to monitor and assess the risk of people on the sex offenders’ register, allowing officers to concentrate stretched resources on those deemed the most dangerous.
At least 14 of the 43 territorial police forces in England and Wales are now using lie detectors, with 14 police officers and 11 staff qualified as polygraph examiners, according to figures obtained by Liberty Investigates.
The data shows 671 polygraph tests were carried out by the 13 forces who provided figures by calendar year, up from 458 in 2018, and a five-year high.
More forces are expected to start using the technology as the College of Policing makes available training through its “polygraph school”.
Image: Polygraph tester Don Cargill reviews Henry’s results
Suspects facing lie detector tests
Testing is “only mandatory by way of conditional caution or a positive obligation of a Sexual Harm Prevention Order or Sexual Risk Order” imposed by the courts, says the National Police Chiefs’ Council, and “any police use of polygraph will form part of a wider and detailed risk management plan tailored to the individual concerned”.
But the University of Northumbria researchers say a non-statutory regime of testing is being carried out by some forces, including on suspects during criminal investigation.
People arrested on suspicion of committing online child sex offences, for example, could be asked to take a test as part of a risk assessment to determine whether they can have contact with children, including their own.
Figures obtained by Prof Oswald and Dr Kotsoglou, using freedom of information requests, show that at least 228 such polygraph interviews were carried out over six years.
Other responses indicated use in “voluntary” risk assessments of convicted sex offenders, including those who apply for removal from the sex offenders’ register, and ambitions to use polygraph testing for more general offences such as violence.
History of the lie detector
The polygraph machine was invented in 1921 by police officer John Larson in Berkley, California, and has been used by US law enforcement agencies ever since and spread across the world.
His work was picked up by Leonard Keeler, who is widely credited as the inventor of the modern lie detector.
In the 1990s, the polygraph entered the computer age as statisticians at Johns Hopkins University developed an algorithm to analyse the data collected.
Jack Ruby, who shot dead Lee Harvey Oswald two days after he assassinated John F Kennedy requested and was granted a polygraph test to try to prove he was not involved in a conspiracy with Oswald – but then FBI-director J Edgar Hoover said the technique was not “sufficiently precise” to judge truth or deception “without qualification”.
Notable failures include CIA agent Aldrich Ames, who passed two polygraph tests while spying for the Soviet Union.
Prof Oswald says: “I think our concern is that should we really in this country be basing really serious criminal justice decisions in a legal system on a scientific technique that is highly contested, to put it mildly, and hasn’t, especially in the policing circumstance, been discussed by parliament?”
The College of Policing says: “The College is working closely with the NPCC to establish a Polygraph School so that policing in England and Wales has access to standardised learning and development in the use of the tool that is tailored to their operating environment.
“The College will develop operational advice so that forces using the tool have a consistent basis on which to do so whilst recognising the relevant legal provisions.”
Image: A new test known as ‘polygraph in a box’ has been developed
What is the future for lie detectors?
The technology has existed in some form for around a century and now Mr Cargill has invented what he calls a “completely revolutionary” Validated Automated Screening Technology (VAST) system – or “polygraph in a box”.
Programmed to find out anything from whether someone has massaged the qualifications on their CV to if they’re a member of an international terrorist organisation, he says the device is as accurate as any polygraph examiner and is already being used by police in the UK.
But the testing time is reduced to around 20 minutes from three hours and can be used with just 15 minutes training.
After filling out a questionnaire, the subject – attached to the device, wearing headphones and sensors on their fingers and palm – is instructed to silently answer “no” to the questions by a person in a recorded video on the screen. A human then grills them about any responses that indicate deception.
“I call it a truth verifier rather than a lie detector because what it’s doing is testing integrity,” explains Mr Cargill.
The technology, he says, would be ideal for use in police vetting and he wants to see it rolled out to areas such as Border Force, where officers could verify someone’s age or country of origin.
The girl, who cannot be named for legal reasons, was stabbed in the back and the arm after going to the class with her younger sister.
She is now campaigning for children to have mandatory first aid training at school in response to the growth of knife crime.
She said she clearly remembers what happened that day.
Image: Flowers and tributes near the scene of the attack a year ago. Pic: PA
“Some of the girls were sat down in a circle making bracelets with the teachers, and a couple of them were getting up to get beads. I was standing between two tables and he came through the doors.
“He stabbed a little girl in front of me and then came for me and stabbed my arm. I turned and then he stabbed my back, even though I didn’t feel it at the time.
“There was a bunch of girls huddled around so I just started pushing them down the stairs, telling them to get out and run.
“I was thinking ‘Where’s my sister?’ and ‘We need to get out’.”
She and many of the other victims ran to the house of a neighbour for shelter. “I just thought that I was going to die,” she said.
Killer ‘looked possessed’
The girl said she can clearly picture Rudakubana that day.
“What I remember most about him is his eyes. They just didn’t look human, they looked possessed. It was kind of like a dream and you’re on a movie set and watching yourself go through it and make these decisions.
“It’s just kind of like adrenaline. People like to think they know what they’d do in that situation but, in reality, you don’t until you’re in it.”
Image: Alice da Silva Aguiar, Elsie Dot Stancombe and Bebe King were murdered in the attack
Six-year-old Bebe King, Elsie Dot Stancombe, who was seven, and nine-year-old Alice da Silva Aguiar died in the attack. It is something she finds difficult to talk about.
“I don’t think I can express how I feel about it,” the girl said. “A lot of anger and sadness.”
In January, Rudakubana was jailed for life and must serve a minimum of 52 years before he can be considered for release.
The chairman of the public inquiry into the atrocity called the attack “one of the most egregious crimes in our country’s history”.
Carrying knives ‘disgusting’
The girl who survived has now launched a campaign, supported by a clothing range called “Go Anywhere, Be Anything” to raise funds, to improve the ability of schoolchildren to help in the event of knife attacks.
“Everyone that’s going out and carrying knives is getting younger and younger,” she said. “And to think that it’s people my age is like disgusting.
“I just want to try and do the best I can to let people know that it’s not okay to do that and that they need to think about what they’re doing and the risks and how they’re harming themselves and other people.”
Her sister, who was also there that day, helped design “Go Anywhere, Be Anything”.
A three-minute silence will be held in Southport at 3pm to mark one year on from the attack. In an open letter to the community, Sefton Council wrote: “This period is incredibly hard for the families of Alice, Bebe and Elsie and all of those children and adults injured or who suffered lifelong psychological impact of witnessing the attack, and we acknowledge the huge impact on their lives, too.
“We must not forget the local people who rushed to support and to our emergency responders. They all remain always in our thoughts.”
It is a sentiment shared by the survivor.
“You live in fear every day that it could happen again,” she said.
“Physically I’m getting better every day and healing. Obviously, my scars stay as a reminder but everyone from that day is going to have mental scars forever.”
The scale of cheap Chinese e-commerce imports flown into Britain without paying any tariffs has become clearer following a Sky News investigation into this new multi-billion pound phenomenon.
We have uncovered the first official estimate of the value of so-called “de minimis” imports into Britain, ahead of an official inquiry into whether this legal clause – which excludes packages worth less than £135 from paying customs duties – should be allowed to continue.
Companies like Shein and Temu have become big players in British retail, not to mention elsewhere around the world, by manufacturing cheap products in China and then posting them directly to consumers, benefiting from the de minimis rules.
Clothing manufacturers in the UK claim that de minimis makes it nearly impossible to compete with these Chinese competitors, raising questions about the viability of domestic textile and apparel production.
However, economists argue that the main beneficiaries of the policy to exclude cheap imports from customs are lower-income households, since it allows them to spend less on their shopping. Removing it, they say, would disproportionately affect poorer families.
The government has committed to an inquiry into the rules, which are also being changed in the EU and the US, but up until now there has been no official estimate of its scale.
According to HM Revenue and Customs data released to Sky News following a Freedom of Information request, the total declared trade value of de minimis imports into the UK in the last fiscal year (2024-25) was £5.9bn.
That was a 53% increase on the previous year (£3.9bn), underlining the scale of growth of e-commerce imports into the UK.
While it is hard to gauge how much revenue this means the Treasury has forgone, an illustrative 20% tariff on flows of that order could raise more than £1bn.
While that sum alone would not fill the fiscal black hole faced by Chancellor Rachel Reeves in the coming budget, it would nonetheless be nearly enough to pay for the government’s recent U-turn on winter fuel allowances.
Sky has also obtained the first television access deep into the supply chain, helping bring those goods into the UK, as it boarded a flight that had just travelled from Chongqing to Bournemouth Airport.
We filmed inside the belly of a plane belonging to European Cargo, one of a number of air cargo firms booming as a result of these trade flows.
The untold story about de minimis is that it hasn’t just had an impact on shopping habits in the UK, or for that matter, the textiles manufacturing sector – it has also changed patterns of distribution.
Struggling regional airports that never saw their passenger numbers recover after the pandemic are now re-establishing themselves as hubs for cargo.
European Cargo is now the single biggest airline at Bournemouth Airport, despite not carrying a single passenger.
Other regional airports like East Midlands Airport and Prestwick in Scotland are seeing rapid growth in flows of trade.
All of which raises the stakes for the government’s inquiry into the de minimis system.
At present, there is no timeline for its decision, but removing the clause would have far-reaching effects across the economy.
The team’s open-top bus will travel along The Mall from 12.10pm.
It will end with a staged ceremony at the Queen Victoria Memorial in front of Buckingham Palace, which is expected to start at roughly 12.30pm and end at 1pm, the Football Association (FA) announced.
The Royal Marines Portsmouth band and the Central Band of the Royal Air Force will perform on the stage and highlights from the tournament will be shown on big screens.
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Liberal Democrats leader Ed Davey was one of those who asked the prime minister if it was “time for that bank holiday”.
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He was referring to comments made by Sir Keir in 2023. When, as leader of the opposition, he wrote on X that there “should be a celebratory bank holiday if the Lionesses bring it home”.
But with estimates suggesting an extra bank holiday would cost the economy £2.4bn, it’s understood such a move isn’t being planned by Downing Street.
‘There is no stopping them now’
The impact of the Lionesses second consecutive Euros title is already being felt across the UK.
At Bearsted Football Club in Maidstone, Kent, a mural of Alessia Russo, who levelled Sunday’s final with a goal in the 56th minute, has been unveiled.
Image: Alessia Russo scoring the levelling goal. Pic: Reuters
The club is where Russo first started playing, and chairman Jamie Houston told Sky News the Lionesses have helped transform the women’s game.
“Five years ago we never had a girl’s football team,” he told Sky correspondent Mollie Malone. “Now we have five separate teams for girls, and boys are accepting of more girls in the game.
“There is no stopping them now.”
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Lynda Hale, who played in the England squad in the first ever international women’s match against Scotland in 1972, reiterated that women’s football has changed drastically since she played.
“When I first started playing there was hardly anyone that would watch,” she told Sky News Breakfast.
“To put on the England shirt and think what we started has grown to this magnitude, and it is still going to grow, is absolutely fantastic. I think the sky’s the limit in women’s football.”
Asked what advice she would have for the current England squad after their win, Ms Hale said: “The girls need to make as many memories as they can and take everything in their stride.”