London terrorist named as teenage Sudesh Amman who was released from prison around a week ago after serving half of his three year sentence for terror offences.
He was under active police surveillance at the time of the attack on Streatham High Road, which police believe to be an Islamist-related terrorist incident.
Three people were injured, with one person in a life-threatening condition.
Prime Minister Boris Johnson said the government would announce further plans for “fundamental changes to the system for dealing with those convicted of terrorism offences” on Monday.
He said the government had moved quickly to introduce measures strengthening its response to terrorism, including longer prison sentences and more money for police, following the attack at Fishmongers Hall, near London Bridge, in December.