An inquiry into the 2017 Manchester Arena bombing concluded on Thursday that there had been a “significant missed opportunity” by Britain’s domestic intelligence agency to take action that might have prevented the attack, which killed 22 people and injured hundreds more after an Ariana Grande concert.
The final, 226-page report said that the spy agency, MI5, had failed to act on two key pieces of intelligence about Salman Abedi, the 22-year-old suicide bomber, in the months leading to the attack. Although the report did not specify what the intelligence was, it rejected earlier claims by MI5 that the information was related to “nonterrorist criminality.”
Had MI5 acted on the intelligence, there would have been a “realistic possibility” it would have taken actions to thwart the attack, the report outlined. However, Sir John Saunders, the chairman of the Manchester Arena inquiry, said that it nonetheless remained “impossible” to reach a firm conclusion on whether or not the bombing could have been prevented — an assessment that drew anger from some of the victim’s families.
“As a result of these failures, at the very least, a real possibility of preventing this attack was lost,” said Richard Scorer, a lawyer representing 11 victims’ families as they stood outside a court on Thursday.
“This is a devastating conclusion for us,” he added.
The inquiry’s report on the atrocity, the deadliest terrorist attack in Britain since the 2005 London bombings, found that Mr. Abedi’s return from Libya just four days before the bombing would have been taken “extremely seriously” had MI5 accurately assessed the intelligence it had.
If an investigation had begun at this stage, the report said, the “attack might have been prevented,” as the spy agency could have placed Mr. Abedi under surveillance and possibly found his homemade explosive device stored in a car in Manchester. Mr. Abedi went to check on the vehicle immediately after landing in Britain from Libya.
MI5’s director general, Ken McCallum, said in a statement on Thursday that he was “profoundly sorry” that the agency had not been able to prevent the attack.
“I deeply regret that such intelligence was not obtained,” he said. “Gathering covert intelligence is difficult, but had we managed to seize the slim chance we had, those impacted might not have experienced such appalling loss and trauma.”
The inquiry also found that MI5 had failed to share key pieces of intelligence with counterterrorism police and that Mr. Abedi had most likely received assistance from someone else in Libya — the first time there was an official conclusion regarding help from abroad.
This assessment contradicted an earlier conclusion by MI5 that no one other than Mr. Abedi and his brother, Hashem, had knowingly been involved in the attack.
For months, the security services presented their timeline of events and evidence for the Manchester Arena inquiry. Much of the information was given behind closed doors for reasons of national security.
The independent inquiry, which the government set up in September 2020, included lawyers, victims’ family members and emergency service groups. It had already published a scathing report on failings by emergency services on the night of the attack. That report concluded the response had been “far below the standard it should have been” and that two of the victims could have survived had there not been an “interminable” wait for treatment.
Mr. Saunders, the chairman of the inquiry, observed a minute of silence before he began speaking, with pictures of the smiling faces of the dead alongside him.