The Manchester Arena terrorist attack on 22nd May 2017 stunned a nation already reeling from another lethal attack on the U.K. Parliament just two months earlier.

Just after 11.30 in the evening, 22-year-old Islamist suicide bomber Salman Ramadan Abedi detonated an improvised explosive device packed with 2,000 bolts as hundreds of teenagers and their parents were leaving a concert by American singer Ariana Grande. The bomb killed 22 people, including many children. More than 1,017 people, again many of them children were physically injured and hundreds more suffered psychological and emotional trauma.

The bombing elicited national outrage and, in response, the Home Secretary in 2019 commissioned an independent public inquiry. The purpose of the Manchester Arena inquiry is to investigate the deaths of the victims. The inquiry is still ongoing but transcripts of its work to date are available online.

One aspect of the inquiry is of particular interest to me and the fight against violent extremism. Four months before the attack, Abedi visited a nearby prison twice to visit convicted terrorist Abdalraouf Abdallah, who was jailed for 9 ½ years in 2016 for assisting those who wanted to travel to Syria to fight for ISIS. The pair were said to be in regular contact by telephone during the time when Abedi was sourcing materials to make his suicide bomb. These calls, made via smuggled phones in the prison, were long in duration. The network of associates involved in visits and in communications between the bomber and Abdalraouf was extensive and includes Elyas Elmehdi, a person still sought by police in connection with the bomber’s plot.

The inquiry spent some time last month looking into the impact that prison associates and radicalisation within prisons may have had on the bomber Abedi. This included expert testimony from an Islamic scholar and evidence from the civil servant who now heads up the new Ministry of Justice and Home Office Joint Extremism Unit (or Jexu).

I was asked by the U.K. government to examine the influence of Islamist extremism in our prisons in 2016 and to make recommendations about what to do to curtail it. One of my most controversial recommendations, accepted by the government but only partially enacted over the intervening years, were separation centres designed to remove the most subversive and harmful ideologically motivated extremists from the mainstream prison circulation to prevent their influence radicalising others.

I have always believed, on the basis of evidence given to me, that there was strong opposition to separation centres by those at the top of the U.K. prison service corporate management. This opposition had a chilling impact on the establishment and operations of the centres, two of which have been either mothballed or never used. The centres are of course controversial and some of the opposition is quite reasonable—principally the risk of housing a small number of highly manipulative and dangerous offenders in the same place. I had argued strongly that this risk was overshadowed by the benefit of removing hate preachers from the targets they wished to groom and the national security risk that behaviour brought to prisons and the wider community. It was therefore something of a vindication to see the evidence presented from the official now in charge of getting a grip on prison extremism some six years after my report landed.

He said, ‘The headline finding in Ian Acheson’s report was that HMPPS (Her Majesty’s Prison and Probation Service) did not have the capacity or the capability to manage the terrorist threat in a way that was commensurate with the risks that were inherent in the system and I think that was a fair conclusion.’

‘So I think the [separation] hypothesis has been proven, not least looking at the impact of the removal of some offenders has had, the impact it’s had on the establishment from which you take them, where we’ve seen marked change in behaviour, presentation and our ability to manage parts of that prison. So I think it is true that there are people with disproportionate impact who aren’t easily replaced if you remove them from the population.’

Abdalraouf Abdallah, although convicted of a very serious terrorist offence, was not held in High Security conditions so his ability to network using illegal phones and visits from people like Abedi was made that much easier. He has refused to cooperate with the inquiry so we can only speculate whether and to what extent his influence directed or motivated the bomber to execute his murderous plans.

The inquiry again throws into question the ability of our protective services to manage risk. There was much mention in the media recently of the efforts now being made to pay more attention to terrorist offenders in prison and their behaviour on release. The number of high-profile failures where extremists who have had contact with our prisons either as visitors or inmates and who then carried out murder and mayhem are unsustainable. The government is at last alive to the potency of prison radicalisation, yet there is much work still to do to ensure that this risk is contained. The inquiry continues, and I will continue to bring to you through the Counter Extremism Project (CEP)’s CounterPoint blog any relevant information that shines a light on the ‘enemy within.’