The UK government has said it will introduce emergency laws to stop terrorists from automatically being released from prison before serving all of their sentences.
It comes after Sudesh Amman, 20, was shot dead by police after stabbing two people in what is believed to have been an Islamist-inspired attack in Streatham, south London yesterday afternoon.
Amman had been released from prison a week before the attack after serving time for spreading extremist material.
British justice secretary Robert Buckland made the announcement today.
He confirmed that Amman had automatically been released halfway through his three years and four month sentence and had not had to go before a parole board.
Under the new emergency legislation, terror prisoners, including ones currently in prison, will not be allowed to be released until they have served two-thirds of their sentence and not until the parole board has agreed.
Mr Buckland also said the government will review whether current maximum penalties and frameworks for terror offenders are "appropriate".
He said a man in his 40s who was stabbed in the Streatham attack is recovering well after fighting for his life.
He said a woman in her 20s who was hurt by glass remains as police shot Amman is still in hospital but recovering.
Amman's mother said today that he was a "nice, polite boy" who was radicalised online and in prison - and revealed she spoke to him just hours before the attack.
Haleema Faraz Khan said her son seemed "normal" when she visited him at a bail hostel on Thursday and he called her before Sunday's attack asking her to make him some food.
Reporting by IRN