Questions loom for the UK’s MI5 spy agency as more details emerge about the suspect in the deadly Reading stabbing.
Khairi Saadallah was arrested minutes after the rampage police now say was a lone-wolf terror attack.
The three people killed have not yet been formally identified but a school in a nearby town said its teacher James Furlong was one of the victims.
British media reports Mr Saadallah, 25, is a refugee who came to the UK after fleeing the civil war in Libya.
Sources told the BBC he was already known to authorities and came to the attention of MI5 in 2019.
According to the BBC, the agency had received information Mr Saadallah wanted to travel abroad – potentially for terrorism – but investigators had not identified a genuine threat or immediate risk.
No case file was opened which would have made him a target for further investigation, the BBC reports.
Mr Saadallah never met the criteria for a full investigation, a security source told AAP.
Initially police and the government said the attack on Saturday night (UK time) did not appear to be terrorism.
But Thames police have since handed the case over to counter-terrorism unit.
Britain’s most senior counter-terrorism police officer Neil Basu said officers worked through the night and had now declared it to be a terrorist incident.
This was an atrocity,’’
– Neil Basu
“From our enquiries undertaken so far, officers have found nothing to suggest that there were any other people involved in the attack, and presently, we are not looking for anyone else in relation to this incident.”
While the motivation for the attack was far from certain, he said there was no intelligence that crowded places were at risk.
British Prime Minister Boris Johnson said he was “appalled and sickened” by the attack.
Britain would change the law if needed to prevent any future incidents, Mr Johnson said.
“If there are lessons we need to learn … we will learn those lessons and we will not hesitate to take action if necessary,” he said.
A witness said the attack began in Reading’s Forbury Gardens when a man suddenly shouted unintelligibly and then veered toward a group of about eight to 10 friends and began stabbing them.
“He darted round anti-clockwise the circle, got one, went to another, stabbed the next one, went to another, stabbed the next one,” Lawrence Wort, 20, told the BBC.
“He stood up and I saw a massive knife in his hand, probably at least five inches (13cm) minimum.”
The attack took place after a Black Lives Matter rally by anti-racism protesters in the park which concluded three hours earlier, but Basu said the two incidents were not related.