Britain’s most senior police officer told a London Assembly committee that it was ‘clearly not possible’ to stop every attack despite police surveillance on the Streatham attacker.
Met Police Commissioner Dame Cressida Dick told the London Assembly Police and Crime Committee that Sudesh Amman was able to stab two people on Sunday (February 2) because surveillance operations are not ‘man-to-man marking’.
Dame Cressida said: “I wish I could assure the public that everybody who poses a risk on the streets could be subject to some sort of thing that would stop them being able to stab anybody ever, but it is clearly not possible.”
She hailed the ‘extraordinary achievement’ shown by officers reacting speedily to the incident in Streatham, as they shot him dead within a minute of the attack starting.
Dame Cressida said ‘strong licence conditions’ for people being released from prison must remain in place even if sentencing law is changed.
In a statement, Assistant Commissioner Neil Basu said: “On Sunday an often invisible part of our policing response – our surveillance officers – calmly ran forward to stop a vicious knife attack in the middle of a busy high street in Streatham.
“I am in no doubt that the quick reactions of our covert officers prevented many more people from being injured, and they exemplified the courage and sense of duty that our officers have shown time and time again in their efforts to protect the public from the terrorist threat.
“And that threat is, despite our best efforts, not diminishing.
“Police and the security services knew the attacker posed a significant risk and we were, unfortunately, proved right in our decision to place him under surveillance. But with 3000 or so subjects of interest currently on our radar and many convicted terrorists soon due to be released from prison, we simply cannot watch all of them, all the time.”
He said he and his colleagues support the plans by ministers to introduce emergency legislation which would keep the most dangerous terrorists locked up for longer, despite concerns about potential legal issues.
Mr Basu added: “When I tell you that ‘communities defeat terrorism’ it is not just a catchphrase. We know from experience that public information and action, including being vigilant, helps saves lives.
“That means vigilance wherever you go, not just the iconic locations and crowded places where we have seen attacks take place in the past. Sunday’s incident is proof that attacks can happen anywhere, and at any time.
“We need people to trust their instincts and to trust us with that information, and not just signs of suspicious activity or behaviour.”
On Sunday afternoon, Amman left a hostel where he was staying at 1.20pm and walked to Streatham High Road.
At approximately 2pm, he stole a knife from a shop and then stabbed two people.
Covert officers who had tracked Amman quickly intervened and shot him dead.
Dame Cressida said these officers remained off street duty for ‘welfare’ reasons.
A man in his 40s remains in a serious but stable condition following hospital treatment.
51-year-old teacher Monika Luftner was discharged from hospital after suffering non-life threatening injuries.
A woman in her 20s was discharged from hospital after receiving minor injuries believed to have been caused by glass following the discharge of a police firearm.
Amman was initially arrested in May 2018 on suspicion of preparation of terrorist attacks.
In November that year, he pleaded guilty to 13 counts relating to the collection and distribution of terrorist material, which saw him sentenced to three years and four months in prison the following month.
He was released from prison on January 23 this year after serving half his sentence, but remained under investigation by the Met’s Counter Terrorism Command.
Around 50 witnesses have been identified and will be asked to provide statements.
However, the police are confident this is an isolated incident that has been contained.