The Golders Green stabbing suspect had been referred to the Government's counter-extremism programme Prevent.
The Metropolitan Police Commissioner Sir Mark Rowley confirmed the Somalian-born suspect had a "history of serious violence and mental health issues".
The 45-year-old suspect was known to the Prevent counter-extremism programme and was subject to a referral in 2020, the Metropolitan Police confirmed.
The case was closed within the year, the force said.
Prevent is the Government-funded agency designed to stop people from becoming terrorists or supporting terrorism.
The Metropolitan Police said: "We can confirm the suspect was known to the Prevent programme and was subject to a Prevent referral in 2020, which was closed in the same year.
"Given the investigation remains ongoing, we will not be providing any further information in respect of this matter at this time and we remain focused on securing justice for the victims of this attack."
Yesterday morning, two Jewish people were stabbed in broad daylight in the north London area in what is being treated as a terror attack.
The Golders Green stabbing suspect had been referred to Prevent
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Officers are currently carrying out a search of an address in south east London.
The Metropolitan Police, alongside members of the local Jewish security group, Shomrim, tackled the suspect.
He was subsequently arrested on suspicion of attempted murder after being tasered and wrestled to the ground, just moments after he tried to attack police officers.
This morning, the Prime Minister said the criminal justice system must respond to the suspected terror attack in a "swift, agile and visible way" during a meeting with policing bosses in Downing Street.
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Sir Keir Starmer has been called on to take action
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Sir Keir Starmer said: "Today is about part of the response which is really important, which is the criminal justice response.
"Because a number of people have been arrested, a number of them go through the criminal justice system, and it’s really important that we are able collectively to demonstrate that the response will be swift and visible."
The Labour leader added "an attack on our Jewish community is an attack on all of us", adding that this was "not a one-off".
"What we saw last night was people being targeted because they are Jewish, I’m absolutely clear about that," Sir Keir asserted.
Sir Keir and his Cabinet are facing growing calls to tackle the surge of antisemitism across the country, particularly in London.
This morning, in the wake of the knife attack, the Government pledged to spend an extra £25million on protection for Jewish communities across the UK.
Whitehall confirmed legislation will be fast-tracked to target individuals acting on behalf of state-sponsored groups in the coming weeks.
As a result, anyone acting on behalf of a state-sponsored group are able to be investigated and prosecuted under the National Security Act.