The mother of a student who was killed in the 2023 Nottingham attacks has said she will “fight to the bitter end” to get to the truth of how Valdo Calocane was free to attack, before the beginning of a public inquiry into the incident.

Barnaby Webber and Grace O’Malley-Kumar, 19-year-old students, and 65-year-old caretaker Ian Coates were fatally stabbed by Calocane on 13 June 2023 in a frenzied attack. Early the next day, Calocane drove a van into pedestrians Wayne Birkett, Sharon Miller and Marcin Gawronski, leaving all three with severe and life-changing injuries.

Calocane, who had been diagnosed with paranoid schizophrenia before the attacks, was sentenced to an indefinite hospital order in January 2024 after admitting three counts of manslaughter on the grounds of diminished responsibility and three counts of attempted murder.

A statutory inquiry will begin on Monday to assess the “events, acts and omissions” before the attacks and what can be done to prevent something similar happening again.

Emma Webber, 53, a communications manager in the NHS and the mother of Barnaby Webber, said she was feeling “overwhelmed, apprehensive [and] anxious” before the first day of the inquiry, and said it had been a “long time coming”.

“What the inquiry has to deliver is truthful answers, but the whole truth – not a version of,” she said. “It is as simple as tell the truth, admit responsibility and accountability when you didn’t do your jobs, or your organisation didn’t do their jobs properly.”

The inquiry will examine Calocane’s NHS healthcare and his interactions with police, or lack thereof, before the attacks.

A report by the Care Quality Commission into Calocane’s care at the Nottinghamshire healthcare NHS foundation trust between May 2020 and September 2022 found there had been a “series of errors, omissions and misjudgments” and, without action, the issues would “continue to pose an inherent risk to patient and public safety”.

An independent review, carried out by Theemis Consulting, also found there had been a “catalogue of failings” in the NHS treatment given to Calocane, including the fact he had had no contact with mental health services or his GP for about nine months before the attacks.

Webber said she could not name a single institution, apart from the CQC, that had “acted with integrity, transparency and candour” since the attacks. “I would say, without exception, we’ve had evasive, defensive approaches from all of them,” she said. “Marking their own homework and closing of ranks to try to keep us quiet.”

Webber anticipated there would be “shocking” revelations during the inquiry, with the expected release of potentially thousands of documents related to Calacone’s care and investigations by police.

The police watchdog is investigating Leicestershire and Nottinghamshire police forces after it was reported that Calocane attacked two co-workers at a warehouse in Leicestershire about five weeks before his deadly attacks in Nottingham.

In a joint statement, the families of Webber, O’Malley-Kumar and Coates said they had been met with “failure and silence” for too long and the inquiry “is about holding those who neglected their jobs to account”.

“We want it to expose systemic neglect with a thorough examination of the missed opportunities by mental health services, law enforcement, and judicial bodies,” the statement reads.

In addition, the families said that they wanted to challenge the legal framework that enabled Calocane to be given a hospital order, instead of a life sentence.

Asked whether she had faith the inquiry would lead to substantial change, Webber said it would be a “conduit to ensuring that meaningful change can happen. I don’t think you could assume.”

“It’s not going to be the end for us, but it’s going to be the beginning of the reckoning and then we have to make sure we see it through,” she said.

Webber said she, or another member of the family, would be attending every hearing of the inquiry, until it is due to conclude in June.

“I’ve been in fight mode and hyper-aware mode for years now. It’s sort of my norm because there’s never been a period where it’s relented or it’s been quieter and we can try and process some of our grief.

“We are doggedly going to pursue this fight to the bitter end and we will get justice which means that my soul will be at rest one day knowing I did absolutely everything I could for him,” she said. “That’s my son and I want to be able to say that I’ve done absolutely everything I can.”