Paranoid schizophrenic Valdo Calocane brought a hammer on to a hospital ward years before he killed three people, an inquiry has heard.
The former student told a doctor at the private mental health facility he packed the hammer in his rucksack because he needed to 'hang items' in his new home, despite him not having a new place to live.
Two years later, he killed undergraduates Barnaby Webber and Grace O'Malley-Kumar, both 19, and caretaker Ian Coates, 65, in the early hours of June 13, 2023 before using a stolen van to try to murder three pedestrians in Nottingham city centre.
Yesterday the London inquiry looking at events leading up to the attack heard from consultant psychiatrist Dr Ajith Gurusinghe, who is the medical director at the Priory Hospital in Arnold, Nottinghamshire, where Calocane was admitted in October 2021.
The inquiry heard Calocane brought the hammer on to the ward on October 10 after a period of leave, with Dr Gurusinghe writing in his witness statement: 'My recollection of his explanation is he picked this up as he was moving to a new property and needed to hang items.'
Counsel to the inquiry Craig Carr put to Dr Gurusinghe that it was a 'completely implausible' explanation because Calocane did not have somewhere new to live.
Dr Gurusinghe said: 'It was plausible in his mind, but we were sceptical. I remember having a conversation with a nurse or somebody that we should keep an eye, he may still be paranoid.
'This was his explanation at the time. We didn't go to challenge him on that.
An inquiry has heard paranoid schizophrenic Valdo Calocane (pictured) brought a hammer to a hospital ward years before he killed three people
'If somebody's insisting that's their version of thoughts or plans, then there's no point challenging at that point.'
Calocane stabbed to death caretaker Ian Coates (left) and students Barnaby Webber (centre) and Grace O'Malley-Kumar (right)
Mr Carr asked the witness whether it was a failure that Calocane bringing the hammer was not recorded as an incident, to which he replied: 'Yes.'
Mr Carr added: 'This is somebody who has come back with something that can be used as a weapon and given an explanation that, Dr Gurusinghe, it sounds like you thought was nonsense.'
The inquiry heard it was also not reflected in Calocane's risk assessment.
Dr Gurusinghe said: 'That should have been included in the risk assessment. It's been missed. I admit it's been missed to be included.'
A Care Quality Commission inspection of the hospital in December 2021 rated it 'inadequate' overall.
Calocane, who admitted manslaughter and three counts of attempted murder, was detained indefinitely in a high-security hospital in January 2024 after prosecutors accepted his not guilty pleas to murder.
The inquiry continues.