Video report by ITV News Security Editor Rohit Kachroo
The murders of Jack Merritt and Saskia Jones in an attack by convicted terrorist Usman Khan near London Bridge on Friday have raised questions over the early release of certain prisoners and the efficacy of rehabilitation programmes.
Here are answers to the key questions regarding his release.
Why was Usman Khan released half way in to his sentence?
Usman Khan and two other men, who planned to raise money to build a terrorist training camp in Pakistan and recruit Britons to attend it, were originally given indeterminate jail sentences for public protection.
Khan was ordered to spend at least eight years behind bars, at which point he would have been assessed for release by the Parole Board and, if found safe, be released on licence for at least 10 years.
If not, he would have been kept in prison, potentially for the rest of his life.
However in 2013 Khan and his co-defendants, Nazam Hussain and Abdul Bosher Mohammed Shahjahan, all from Stoke-on-Trent, successfully appealed against their sentences.
They argued that they had been unfairly classed as more dangerous than other members of their terror cell, who were plotting to bomb the London Stock Exchange.
As a result, Khan was given a fixed jail term of 16 years, with an extended licence period of five years.
This meant he was automatically released after serving half his jail term, but would have remained on licence for 13 years after release.
If he broke the conditions of his release during this time, he could be sent back to prison.
Would the Tories’ proposed changes to automatic release affect a case like Khan’s?
The Conservatives say criminals sentenced to at least four years in prison for crimes which carry a maximum life term would no longer be released at the halfway point.
Instead, those offenders will be required to serve two-thirds of their sentence behind bars.
But for a case like Khan’s, the type of indeterminate sentence that he received was scrapped in 2012, and the current equivalent is an extended determinate sentence.
Under that system, defendants given terms of less than 10 years are already automatically released after serving two-thirds of their sentence, so the changes would not affect them.
What attempts were made to stop Khan re-offending?
Khan appears to have hoodwinked the authorities into thinking that he had changed his ways.
He was attending a Cambridge University conference on prisoner rehabilitation when witnesses said he “flipped” and launched his attack.
The event was part of the Learning Together scheme, which allows offenders and students to study alongside one another.
While in jail in 2012, Khan wrote an apparently contrite letter to the Home Office asking to take part in a deradicalisation programme, claiming he had been “immature” when he committed his offences.
He said that he wanted to live as “a good citizen of Britain”.
But, it has also been reported that he refused to take part in deradicalisation programmes while in high security jail Belmarsh.
On release, he would have taken part in the Government’s Desistance and Disengagement Programme, that aims to stop offenders taking part in terrorist activity and to move away from terrorist ideologies.
He was also wearing an electronic tag at the time of the attack, which is designed to enforce curfews. He would reportedly have had to report his plans to travel to London to police.