Good. Stewart presided over a truly catastrophic failure, leading to the murder of three young girls. But Prevent’s problems go much deeper than the man at the top.

A so-called learning review, published in February, showed that Prevent had misspelt Rudakubana’s surname in its database, something that may have hindered its ability to assess the threat he posed. We also know that Rudakubana was referred to Prevent three times between 2019 and 2021, due to his morbid fascination with knives, terrorist attacks and school shootings. Yet Prevent still closed his case ‘prematurely’, three years before he went on to murder and maim innocents at a Taylor Swift-themed dance class.

Rudakubana was clearly a ticking timebomb. And Prevent failed in its fundamental task to protect the public. His case was closed because he lacked any coherent terroristic or religious ideology – even though Prevent also caters to would-be killers of this kind.

This is not the first time Prevent, a crucial pillar of the UK’s counter-extremism apparatus, has come in for stinging criticism. William Shawcross’s independent review of Prevent, published in 2023, concluded that the scheme too often ‘bestow[ed] a status of victimhood on all who come into contact with it’. Shawcross argued that it needed to shift focus from ‘safeguarding’ to ‘protecting the public from those inclined to pose a security threat’.

Moreover, there is an increasing threat posed by non-ideological actors, which Prevent is struggling to grasp. The Shawcross review referred to ‘the sharp uptick of “Mixed, Unclear or Unstable” (MUU)’ referrals to Prevent. This often-overlooked category essentially describes a ‘salad bar’ form of extremism, in which different, disparate elements are combined in the mind of a killer. Tracking those with an uncertain, incoherent combination of motivations poses significant challenges for authorities accustomed to dealing with more traditional Islamist or far-right forms of extremism.

Rudakubana seems to fall into the MUU category. He displayed a chilling obsession with acts of terror, genocidal violence and school shootings. He possessed an academic study of an al-Qaeda training manual, material on Nazi Germany and anti-colonialist literature – suggesting the through-line here wasn’t ideology or religion but a revelling in mass violence itself.