Ministers hope the scheme — targeting the 750 vilest sex fiends — will catch those who are reoffending.
Blood pressure, heart rate and breathing will be measured to make sure the monsters are telling the truth about where they have been and what they have been up to. Tests that set alarm bells ringing could see the perverts returned to jail.
In a Ministry of Justice pilot scheme, sex offenders made TWICE as many admissions when put through the polygraph tests, compared with another group.
Many even confessed to breaches of their licence conditions BEFORE being hooked up to the machines because they knew they would be caught out.
US forensic psychiatrist Don Grubin helped run the trial in the Midlands between 2009 and 2011. He told The Sun yesterday: “I have no doubt serious offences have been prevented through use of this technology.”
One freed rapist was returned to jail after admitting he had been performing sex acts in public and was mixing with other sex offenders.
In another case a paedophile revealed he had recently started dating. Investigators later found he was regularly undressing in front of his new girlfriend’s young daughter. And a third pervert admitted he had been viewing child abuse images online since finishing a jail term for the same offence.
He was caught out by officials who suspected he cheated his first test by holding his breath. They gave him a second test — and he was forced to admit accessing the sickening images.
His case echoed that of Jon Venables, 30 who was recalled to prison two years ago for viewing sickening child abuse images while on life licence for the murder of two-year-old James Bulger in 1993.The worst of them depicted penetrative sex with seven- or eight-year-olds. He was also in contact with known and convicted paedophiles online.
Ministers hope to push plans for the tests through Parliament and bring in the £4,000 polygraph machines by 2014. Offenders who refuse to take the tests will be in breach of their licence conditions and could be returned to prison.
Justice Minister Crispin Blunt confirmed last night: “We will be making the request to Parliament and in due course we will mandate it for the 750 most serious offenders.”