Chilling footage of undercover police trailing the Streatham attacker moments before he struck out has emerged online.
Sudesh Amman was captured on residential CCTV footage shortly after he left a bail hostel following his release from prison in January.
The 20-year-old can be seen walking down a street close to Streatham High Road where he stabbed two people and revealed a fake suicide bomb vest, Sky News reports.
Moments later, a plain-clothed police officer riding a purple motorbike follows.
Amman appears to be wearing grey joggers, a black hooded jumper with a large image on the front and a woolly hat.
The Metropolitan Police said in a statement: "Armed officers, who were part of a proactive counter-terrorism surveillance operation relating to the attacker, were following him as he left an address in the Streatham area at shortly after 13:20hrs.
"He then made his way on foot and was observed entering a shop on Streatham High Road shortly before 14:00hrs."
Amman is believed to have stolen a knife from a shop, removed the packaging, and stabbed two passers-by.
He was shot by officers and the policeman on the motorbike was among the first on the scene.
A number of special intelligence officers were used to stop Amman in his tracks before the incident escalated further.
SAS military advisers helped police locate and target the crazed knifeman after it became clear his mission was to unleash an attack.
Soldiers were also involved in the operation to stop Amman, who was only released from prison around a week before after serving half of his sentence of three and a half year, four months, for distributing extremist material.
At least 20 Islamist suspects are under intense MI5 and police surveillance amid fears they could strike at any time, the Mirror previously reported.
Neil Basu, the Metropolitan Police assistant commissioner, warned that with many convicted terrorists soon to be released from prison, the forces "simply cannot watch all of them".
