When U.K. police confirmed the identity of the Manchester suicide bomber as Salman Abedi, it was not entirely a surprise. U.K. Home Secretary Amber Rudd admitted Wednesday that Abedi was "somebody that they had known," but only "up to a point" – meaning that while something had alerted intelligence officials to his activity, he was not deemed a significant enough threat to warrant close tracking of his movement.
The BBC reported that Abedi popped up on a list five years ago for terror activity and resurfaced earlier this year, but that wasn't enough to stop him from walking into Manchester Arena Monday evening and setting off a nail bomb that killed 22, including an 8-year-old girl and himself. The fact that Abedi was on any list at all has reignited the debate about whether the devastating attack could have been stopped, and raises questions about the value of intelligence in stopping future attacks.
Security experts speaking to VICE News all say that while it is too early to come to any definite conclusions, all the indications point to some sort breakdown in the system which should have flagged 22-year-old Abedi as a threat.
"At this point, there seems to have been some sort of intelligence failure, in that he had not been given the priority that the threat warranted," Patrick Bury, a former NATO analyst and lecturer in security at Cranfield University, told VICE News.
In the wake of such tragedies, focus typically falls on intelligence services such as GCHQ and MI5, particularly when the perpetrator is someone who had previously been flagged as a threat – as with the recent Westminster attack.
"There has been a pattern we have seen over the past number of attacks, that the perpetrators have one way or another come across the security services radar, but because of prioritization issues or resources, it leads to them not being made a high priority at the time," said Huw Dylan, a lecturer in intelligence studies and international security at King's College London.
There are many triggers and indicators that intel operatives will look for when considering if a potential target warrants the full "signal intelligence" treatment – when electronic communications are tracked. While police forces and intelligence agencies can monitor some online usage, travel patterns, and any suspicious changes in behavior, much of the most important information will normally come from the suspect's community.
"It seems like a lot of the intelligence that leads to people considered a threat actually comes from the community — friends, neighbors, etc. — who have been observing changes in people's behavior and alerting the authorities," Dylan said.
Part of the problem in this case appears to have been that Abedi was not a main actor in any of the groups being tracked by GCHQ or MI5. Indeed, the BBC reported Monday that he was seen by officials as a mule, simply there to carry the explosive. Such a target is very hard to track. "If someone is operating on the fringes and isn't seen as a major threat, the resources in relation to signal intelligence will not be allocated to them," Bury adds.
If travel and behavior are two things which could have flagged Abedi as a threat to U.K. intelligence agencies, it appears there was sufficient evidence of both in recent weeks.
A neighbor of Abedi's in South Manchester had noticed the family acting strangely in recent weeks, according to a report in the Telegraph, "They have been acting strangely. A couple of months ago he was chanting the first kalma [Islamic prayer] really loudly in the street. He was chanting in Arabic. He was saying 'There is only one God and the prophet Mohammed is his messenger.'"
Separately, the Times reports a school friend of Abedi saying: "He went to Libya three weeks ago and came back recently, like days ago." It is unknown if the police were aware of the change in Abedi's behavior or his recent trip to Libya.
Bury, who has studied the security situation in Libya extensively, says that if he did in fact travel to Tripoli in recent weeks, that's something which should have immediately set off warning signs for intelligence officials.
"I understand Libyans want to go home, but I have traveled to Libya and it is bloody dangerous at the moment. So how people are able to get into the U.K. [from Libya] is kind of questionable," Bury said, adding that there are a number of hard-line Islamist groups operating in the Libyan capital, including Ansar al Sharia, which is linked to Islamic State.
Because the method as to which targets are prioritized is necessarily done in secret, the public will often never know when the intelligence agencies actually prevent an attack. The U.K. has been relatively terror-free since the attacks on London mass transit in 2005. But when a decision to monitor somebody has to be made without all the vital information, there is always a chance that authorities will get it wrong.
"Whenever you are dealing with intelligence, you are dealing with an incomplete picture," Raffaello Pantucci, director of international security studies at the Royal United Services Institute, told VICE News. "You never get a full understanding of what exactly is going on because you can't get into people's heads."
The U.K. has now raised its threat level to "critical" — meaning the government believes another attack is imminent. There will now be a huge amount of pressure on the intelligence agencies to prevent future atrocities, only exacerbated by the growing assumption that Abedi was not acting alone.
For intelligence officials now trawling through information held on Abedi, much of their time will be spent reassessing how the facts they had at the time were interpreted. "Whenever something like this happens, it will immediately make people question what decision they will make, and it will make people revisit old information," Pantucci says. "Clearly this individual had been less prioritized, so immediately the question will be 'Who else does he know?' or 'Who is in his network and do we need to worry about them?'"
Despite any possible failures in the handling Abedi's case, Bury points out that the U.K.'s intelligence agencies have prevented a mass terrorist attack in the U.K. for over a decade, despite the threat being higher than it ever has before.
"British intelligence and security services have the reputation of being the second best, if not the best in the world," Bury said. "They are widely viewed across Europe and even in the U.S. as an example of best practice. Their ability to contain the threat since 2005 has been remarkable."