A man who killed three people during a 2023 knife attack in Nottingham had attempted to hand himself into MI5 for arrest two years earlier, an inquiry has heard.

Valdo Calocane, 34, fatally stabbed Grace O’Malley-Kumar and Barnaby Webber, both 19, and Ian Coates, 65, during a stabbing spree in the city on 13 June 2023.

He admitted to manslaughter on the basis of diminished responsibility and was sentenced to indefinite detention at a high-security hospital.

The inquiry, which is being held in London, heard on Tuesday that, in May 2021, Calocane had attempted to hand himself in to MI5 at their headquarters at Thames House in central London.

PC Graham Foster, who confronted Calocane outside after he had rung the building’s intercom, told the inquiry Calocane had informed a member of security that he wanted to be arrested and speak to the police.

When asked why he did not question Calocane on why he wanted to be arrested, Foster told the inquiry he had aimed to “build a rapport” as he thought that was the best way to see if he was “offering any other information”. He described Calocane as “calm, compliant and coherent”.

Supt Lorraine Busby-McVey of the Metropolitan police told the inquiry that Calocane was “looked at” by the Fixated Threat Assessment Centre (FATC), a unit that examines threats from fixated individuals, but he did not meet their threshold to be assessed further.

Busby-McVey said that an intelligence report from the FTAC regarding Calocane’s visit to Thames House was passed to Nottinghamshire police the next day, 1 June, but that the force did not then carry out their own assessment. Busby-McVey said that was something she “would have quite liked” to have happened.

She also said that the report, though sent to the force, was not available to all the officers in it. A new system to improve the quality of information shared between police forces had since been put in place, she said.

The inquiry also heard from Calocane’s former flatmate, named only as Sebastian, who said reports he made to Nottinghamshire police that Calocane had accosted him at their flat were ignored.

“He grabbed hold of my shirt and my arm and pushed me against the wall and said some confusing words,” he said. “Then he basically said someone would contact me and that if they contacted me, I should tell them that VC would find them.”

Sebastian later contacted Nottinghamshire police. An officer told him that they would file a report, which would be flagged to an agency, but they did not specify which.

As well as being grabbed by Calocane, Sebastian told the inquiry that he suspected Calocane of stalking him and attempting to enter his bedroom at night.

Sebastian said that he began to lock his door after the incident, saying “I know he is aggressive and that he could harm me again out of nowhere”. He also reported Calocane attempting to enter his room to the officer he had contacted previously, but did not get a response, which he found “very surprising” and “weird”.

He said when he heard about the Nottingham attacks that he suspected Calocane could have been the perpetrator before his identity was confirmed.

The inquiry continues.