A special constable with Nottinghamshire Police was previously sacked for viewing bodycam footage showing the aftermath of the attacks.
In the June 2023 attack, Calocane killed Mr Webber, Ms O'Malley-Kumar and Mr Coates, before using Mr Coates's van to drive into three pedestrians - Wayne Birkett, Marcin Gawronski and Sharon Miller - in the city centre.
Calocane was sentenced to a hospital order in January 2024 after admitting manslaughter on the grounds of diminished responsibility.
Following Calocane's sentencing, the families were highly critical of the police and Crown Prosecution Service (CPS).
A subsequent review into the CPS found that while prosecutors had been right to accept Calocane's pleas of manslaughter on the basis of diminished responsibility, they could have handled the case better.
There have been a number of other reviews, including an investigation into the NHS mental healthcare and treatment he received prior to the killings, published in early February.
This identified a catalogue of failings, including that Calocane, who has paranoid schizophrenia, was not forced to take his anti-psychotic medication in part because he did not like needles.
And it found he had no contact with mental health services or his GP for about nine months prior to the killings - after he was discharged when he repeatedly failed to engage with them.
Shortly after the findings were published, it was announced that a judge-led public inquiry into the attacks would take place "within weeks".
This was welcomed by the families, who tearfully applauded the news during a meeting at No 10 Downing Street and called it a "watershed moment".
They were told by Prime Minister Sir Keir Starmer a "number of different agencies" would be scrutinised.