The security services were guilty of “a significant missed opportunity to take action that might have prevented” the Manchester Arena bombing, according to the chairman of the inquiry into the atrocity.

A report published by former high court judge Sir John Saunders, the third and final from his inquiry, looked at whether MI5 and counter-terror police could have prevented bomber Salman Abedi from carrying out the attack.

Inquiry latest: Bomber’s family held ‘significant responsibility’ for his radicalisation

The inquiry had heard Manchester-born Abedi had been on the radar of the security services for seven years before the bombing.

Twenty-two people died and hundreds were injured in Abedi’s suicide bombing at the end of an Ariana Grande concert on 22 May 2017.

The report also covered the radicalisation of Abedi and the planning and preparation for the attack.

But the focus for many of the families of the victims has been the failings of the security services to prevent the attack.

In his report, Sir John said: “There was a significant missed opportunity to take action that might have prevented the attack.

“It is not possible to reach any conclusion on the balance of probabilities or to any other evidential standard as to whether the attack would have been prevented.

“However, there was a realistic possibility that actionable intelligence could have been obtained which might have led to actions preventing the attack.”

He said the reason for the missed opportunity included a failure by a Security Service officer to act swiftly enough.

‘Devastating conclusion’

The inquiry, he said, also identified problems with the sharing of information between the Security Service and counter-terrorism police.

“It remains quite impossible to say whether any different or additional action taken by the authorities could have prevented the attack. It might have done; it might not have done.”

Families of the victims described the report as a “devastating conclusion”.

In a statement they said: “Today’s report has been deeply painful to read, but also eye-opening. On the issue of the preventability of this attack, inevitably the report provides less information than we would have wanted. But it is now very clear that there was a failure to properly assess key intelligence about Salman Abedi; a failure to put it into proper context; and – most catastrophic of all – a delay in acting on it.

“As a result of these failures, at the very least, a real possibility of preventing this attack was lost. This is a devastating conclusion for us. The failures exposed in this report are unacceptable.”

They added: “It is clear that Salman Abedi should have been referred to Prevent (counter-terror programme). It is clear that the education system needs to be more vigilant in picking up signs of radicalisation. It is clear that Didsbury mosque turned a blind eye to extremism in its midst. Sir John’s report today contains many lessons; we must heed every one of them and make the necessary changes urgently.

“On 22 May 2017, thousands of people left their homes to attend a concert at Manchester Arena. 22 of those would never return home. Those killed and injured in this murderous attack had every right to feel safe and protected, but as this inquiry has demonstrated, they were failed at every level – before, during and after this horrific attack.”

‘Intelligence was not shared’

A number of MI5 and police counter-terrorism detective witnesses gave evidence behind closed doors during the 17-month inquiry. The sessions were held in secret in an effort not to compromise national security.

A summary of some of their evidence was later made public but the so-called “gist” did not reveal any details about the intelligence received by MI5 in the months before the attack.

But Sir John’s report identified the “principal missed opportunity” as two pieces of intelligence received by the Security Service in the months prior to the attack, “the significance of which was not fully appreciated at the time”.

Both of those pieces of intelligence, which were not disclosed in the report, were assessed to relate to “non-nefarious activity or to non-terrorist criminal activity” on the part of Abedi.

Neither piece of intelligence was shared by the Security Service (MI5) with counter-terror police in the northwest. If further investigative steps had been taken as a result of one of those pieces of intelligence, Sir John said, “this would have increased the overall prospect that the attack would have been prevented”.

The other critical piece of intelligence, Sir John said, “gave rise to the real possibility of obtaining information that might have led to actions which prevented the attack. We cannot know what would have happened, but there is at least the material possibility that opportunities to intervene were missed”.

When Abedi returned to the UK from Libya four days before the attack, he said, that information could have led to his Nissan Micra, which contained the explosive, being followed by police.

When the second piece of intelligence was received, Sir John said, the Security Service officer should have discussed it straight away and written their report on the same day but did not do so.

“The delay in providing the report led to the missing of an opportunity to take a potentially important investigative action. I am satisfied that such an investigative action would have been a proportionate and justified step to take. This should have happened,” he said.

Sir John said the security service and police “underestimated the risk” of returnees from Libya because of their focus on those from Syria.

Abedi’s radicalisation

The inquiry identified other missed opportunities to intercept Abedi.

The Security Service had first received information relating to him in December 2010, he was treated as a “subject of interest” in 2015 and had contact with a convicted terrorist and “known radicaliser” Abdalraouf Abdallah.

Messages between Abedi and Abdalraouf Abdallah were not given to the security service by counter-terror police. They should have been, Sir John said, as this would have added to the picture about Abedi’s “actions and intentions”.

A meeting to consider further investigation of Abedi had been scheduled for 31 May 2017, nine days after the bombing.

In his report, Sir John said the Abedi family – father Ramadan, mother Samia and elder brother Ismail – held “significant responsibility” for the radicalisation of Salman Abedi and his younger brother Hashem. Hashem Abedi is serving a minimum of 55 years for helping to plan the attack.

“Salman Abedi’s radicalisation journey into operational violent Islamist extremism was primarily driven by noxious absences and malign presences,” Sir John said.

“Noxious absences included a prolonged disengagement from mainstream English education and parental absence. Malign presences included the ongoing conflict in Libya and engagement with a radicalising peer group.”

‘Missed opportunities’

Sir John’s first inquiry report, published in June 2012, focussed on security arrangements on the night of the bombing and highlighted a string of “missed opportunities” to intercept Abedi before he detonated his device.

His second report, published in November last year, was highly critical of the emergency service response. He judged that one of the victims, John Atkinson, would have probably survived had it not been for the inadequate response. There was a “remote possibility” that the youngest victim, eight-year-old Saffie-Rose Roussos, could have lived.

Read more:
The mistakes made at Manchester Arena as emergency services responded to the terror attack
The missed opportunities by security to stop Salman Abedi on night of Manchester Arena bombing

In his final report, Sir John said, Abedi “left behind no message to explain why he carried out the attack. The evidence I heard does not provide a definitive answer as to why he did what he did”.

He said the national security interest of holding some parts of the inquiry in private “has been particularly difficult for the bereaved families”.

He added: “I am sorry that I have not been able to reveal in my open report everything I have discovered. I know that what I have revealed, while increasing public knowledge, will raise other questions.”

Sir John made a number of recommendations in his final report.

He said that no one should underestimate the “very difficult job” of security services, particularly with the emergence of lone actor terrorists whose activities are more difficult to track.

Dozens of so-called “late-stage attack plots” had been disrupted since the start of 2017, he said.

“Having said all that, if the Security Service or counterterrorism policing make mistakes, then these need to be identified and steps taken to put them right.”

Home Secretary Suella Braverman said she is “committed” to working with MI5 and the police to “do everything possible” to prevent a repeat of the “horrifying” attack.