Prison staff considered Fishmongers' Hall attacker Usman Khan safe to join an inmate education programme whose academics he would later stab, despite intelligence he was still involved in radicalisation and gang-related violence, an inquest heard.
Senior staff at HMP Whitemoor in Cambridgeshire concluded Khan could join a creative writing course run by Learning Together, said Will Styles, who was prison governor before the convicted terrorist's release in December 2018.
Mr Styles said he was confident he was "given a picture" of Khan's behaviour in prison at the time and he was aware the 28-year-old from Stafford was "a difficult and risky character" but the decision was made to allow him to enrol.
Khan would go on to be considered a "success story" for Learning Together, the inquests previously heard, so much so that he was invited to a celebration event in central London on 29 November 2019, where he fatally stabbed Cambridge graduates Jack Merritt and Saskia Jones.
Giving evidence at the inquests into their deaths, at City of London's Guildhall on Friday, Mr Styles said: "The concern was he was a [terror] offender.
"Consideration was given to risk, opportunity, benefit.
"Some of the coursework involved ethics, and there was discussion whether someone with a history of extremist ideology would be able to participate respectfully in a discussion about ethics."
He said it was concluded that Khan should be able to join Learning Together, despite intelligence he had been involved in radicalisation inside prison, and that he was considered something of a gang member.
He said: "I thought the risks presented were controllable and the potential benefits for Usman given his fairly imminent release - I thought it was a positive opportunity for Usman and for us."
The inquest jury was shown a police document which stated a prison governor – believed to be Mr Stiles – told a a Department for Work and Pensions employee Khan was "completely reformed" at Whitemoor in summer 2019.
Mr Styles said he did not recall the conversation, but he may have said it.
The inquest jury also saw a draft of a letter in February 2019 seeking an award for Learning Together's work in Whitemoor, citing Khan as a positive example.
Nick Armstrong, representing the family of Ms Jones, accused Mr Styles of ignoring the "hard-headed" risk analysis.
Mr Styles said Learning Together “did more than anything else in his time at Whitemoor ... to help him desist and disengage with extremist behaviour.”
The inquest jury previously heard evidence of how Khan's behaviour improved in the final year of his eight-year sentence for plotting a terror training camp in Pakistan.
Khan killed Mr Merritt and Ms Jones and injured three others at Fishmongers' Hall. He was then chased down London Bridge and disarmed by three civilians before being killed by police.
Additional reporting by agencies