Detectives are urgently investigating why a man armed with a sword went on a 22-minute rampage in east London, killing a 14-year-old boy and wounding four other people in an apparently random attack.
The teenager was fatally injured when the suspect swung at him with the weapon on Tuesday morning.
Police were first called to reports of a vehicle being driven into a house in the Thurlow Gardens area of Hainault just before 7am. The 36-year-old suspect was arrested about 22 minutes later.
Two police officers sustained “significant” but not life-threatening injuries, while injuries sustained by two members of the public are also not deemed to be life-threatening.
Ch Supt Stuart Bell of the Met appealed for time to find answers. “I know the families of those involved, the local and wider community and many across London will want to know why this terrible incident occurred,” he said.
“And it’s our job to find that out and we will. I’m committed to providing those answers when we can and I would ask for some patience while this important work is carried out.”
Police said the suspect had been arrested on suspicion of murder, but was not yet fit to be interviewed because of injuries he sustained when his van collided with a building.
“We know there is speculation about his background, including police contact with him,” said the Met’s assistant commissioner, Louisa Rolfe.
“Despite urgent checks of our system today, we have found no trace of a prior incident involving him so far, but we will of course continue to make those inquiries.
“As a matter of urgency we are trying to understand exactly what happened and why.”
Counter Terrorism Policing headquarters has assessed the incident as not being terrorist-related and detectives are satisfied the man was acting alone. Police are investigating whether the suspect has a history of mental ill health.
The spree of violence on Tuesday had a national impact. Buckingham Palace said the king had asked to be updated on developments.
“His thoughts and prayers are with all those affected – in particular, the family of the young victim who has lost his life – and he salutes the courage of the emergency services who helped contain the situation,” a statement said.
The incident came 48 hours before voting begins in London’s mayoral election in which crime – including knife crime – is a key issue.
The mayor of London, Sadiq Khan, said he was “devastated” by the news from Hainault. “The police officers and emergency services showed the best of our city – running towards danger to protect others and I thank them from the bottom of my heart,” he said.
The prime minister, Rishi Sunak, said: “This is a shocking incident. My thoughts are with those affected and their families.
“I’d like to thank the emergency services for their ongoing response, and pay tribute to the extraordinary bravery shown by police on the scene. Such violence has no place on our streets.”
Knife crime in London rose last year, though it is still below levels reached before the Covid lockdowns. Homicides by London standards remain relatively low, 110 last year compared with 120 in 2015 when the Conservatives last held the mayoralty under Boris Johnson.
Eyewitness accounts suggest the 14-year-old was killed after walking past the scene and being swiped at with the sword. Locals tried to save the boy, but he later died from his wounds in hospital.
One resident said she saw a man standing outside her home next to a body and brandishing a sword in front of two unarmed police officers and an ambulance.
“He was wielding his sword trying to attack the police but then they sprayed him and he ran away,” she said. “He was shouting at the police: ‘Do you believe in God?’, also at the ambulance.”
In another video the suspect is heard and seen saying “Is there anybody here who believes in God?” while standing next to a wounded person.
Police are investigating whether he tried and failed to enter a home, before setting off on foot in the direction of the nearby Hainault tube station, filling up with rush-hour travellers.
Dramatic footage shows him clambering on roofs trying to flee police encircling him, with one resident shouting for his neighbours to lock their doors, as fear and panic gripped the quiet residential area on the east London and Essex border.
The suspect was eventually cornered near a front driveway, clutching the sword, before being tasered twice, over-powered and handcuffed.
The man was arrested on suspicion of murder but spent most of the day being treated in hospital for injuries. His wounds, some at least caused by an airbag deploying, have meant police could not formally interview him.
Four people remained in hospital, including two police officers – one man and one woman – both of whom required surgery.
Armed officers were called to the scene, but it was their uniformed colleagues who halted the attack and bore the brunt of the danger.
One has injuries consistent with defending himself against a blade being swung in his direction. The officer was more seriously injured, suffering a serious limb injury.
