Police predicted that a convicted terrorist would attack the public when he was released from prison, less than a month before he went on a knife rampage in south London, an inquest has heard. MI5 and police officers discussing intelligence about Sudesh Amman said an attack would be a case of “when, not if,” two weeks before he was released from Belmarsh prison for terror offences in early January 2020. Police tried to block the 20-year-old’s release, because of intelligence that he wanted to stage an attack. He had been jailed in May 2018 for terrorism offences, but he was released halfway through his sentence. A report by the Metropolitan police’s Terrorism Offender Management Unit, a fortnight before Amman’s release concluded he was one of “the most dangerous individuals we have investigated”. Amman struck on 2 February, stabbing two people in Streatham High Road, south London. He was under surveillance due to the risk he posed to the public, and was shot by police who had been following him. He was wearing a fake suicide belt fashioned from items bought from Poundland two days earlier, including Irn-Bru bottles, parcel tape and kitchen foil. Police had considered arresting him after he was seen buying the items, but after a meeting with MI5 decided there was insufficient grounds for arrest. The senior police officer leading the investigation into his release from prison on 23 January, known only as HA6 to protect his identity, said an arrest would probably have risked undermining the undercover investigation. He said: “Arresting him would have been a short-term measure. I would have envisaged he would have been released back into the community. “He would be aware of our covert operation around him and that would make our job a lot harder. We would have only disrupted ourselves. [The arrest] was discounted and we decided to continue with the covert operation.” Later in the hearing, Rajiv Menon, representing Amman’s family, asked Carina Heckroodt, head of the London Extremism Gangs and Organised Crime Unit in the National Probation Service, whether her failure to recall him was a “a most serious missed opportunity in this case.” She replied: “I disagree, it was not a missed opportunity.” The senior officer told the court that Amman’s behaviour in the moments before he struck, wearing an empty bag over his torso, walking slowly and “peculiarly” was not reason to intervene. “Without anything to suggest he is in the process of attack planning, it would have been a short-term disruption.” This week the coroner, Mr Justice Hilliard, heard that intelligence services had concerns about Amman’s behaviour in prison, specifically his allegiance to the Islamic State, his apparent desire to radicalise others and his reluctance to engage with the authorities. It was also revealed that just three days before the knife attack, he indicated he was no longer a risk, telling his mentors that he had realised that those who committed terrorist acts ended up “pushing people away” from Islam. Amman, who was from Coventry and of Sri Lankan descent had also said he wanted to kill the Queen. An extremism risk guidance prepared before his release highlighted the risk of him staging an attack. Heckroodt’s witness statement, read before the jury at the Royal Courts of Justice in central London, said that during a team meeting on 9 January, “the police said that Amman was a high threat and that an attack would be when, not if”. Police told the inquest that they did not search Amman’s room at his probation hostel because they did not want him to realise he was under surveillance. His inquest, which is scheduled to last another two weeks, has been adjourned until Friday.