A woman stabbed to death in the street in Maida Vale was killed by her ex husband despite having a restraining order against him, relatives have claimed.
Family today named the pair as Yasmin Wafah Chkaifi and her ex-husband Leon McCaskre.
Police confirmed the pair had been in a relationship.
She had a panic button installed at her home and both police and social workers were aware of the situation, it was claimed.
Yasmin Chkaifi, 43, is believed to have been stabbed up to 10 times by Leon, 41, before a man in a blue Renault ran out to try and stop the knifeman in his tracks.
The driver then drove into Leon but both he and Ms Chkaifi died at the scene.
Scotland Yard said he has been “fully cooperative with the investigation” and has been bailed until late February while the evidence is evaluated.
They thanked the driver from the scene of the brutal attack and called him “a hero” for stepping in and trying to stop the carnage.
In a statement issued on behalf of the family, a cousin who did not want to be named said: “He has harassed her for three years and was supposed to appear in court last week but missed his court date.
“They were married for three years but then divorced three years ago. She had a restraining order out against him.
“She had a panic alarm in her house and he was extremely abusive. The police were aware of his abuse and social workers were involved.
“She had no one to protect her at the time she died and he was a violent man. His mum was aware of the abuse.
“Her new partner was an angel.”
They described the car driver as a “hero”.
The cousin said: “He saw the killer trying to get away and wanted to stop that.
“We want to thank him for risking his life. He should not have been arrested, he is a hero. Maybe the Queen can give him an award.
“Our family are very proud of him.
“We don’t want to say more about her, we just want to speak out to let everyone know he killed her.”
Another cousin and her two sons were at the scene when she gave the statement.
Neighbours paid tribute to the woman, who until recently worked at St Augustine’s High School, who was described as a “very kind woman”.
The mum, 43, had two sons aged 16 and 18 and is believed to have moved in with a new partner.
One neighbour said: “She was called Wafah Chakefi and she was my friend. I am too upset to talk about what happened.”
Another neighbour who did not want to be named said: “She was a very kind woman. I knew her as a neighbour rather than a friend but I would see her in the morning when we took the children to school.
“She was a very good woman, she was friendly, funny and had a good character to her.
“She worked at the school my children go to which was St Augustine’s High School.”
Another neighbour who did not want to be named said: “She was really nice and kind. When I was younger sometimes we would shout at each other through the walls.
“Yesterday I saw her close friend crying. I didn’t know her personally but everyone in the block knew her.
“I know she was married for a long time but then got divorced or separated.”
Det Ch Insp Neil Rawlinson, of the Met’s Specialist Crime Command, said:“We are gaining a clearer idea of what happened at the scene thanks to information supplied by the public and by reviewing CCTV.
“Firstly, it is apparent that members of the public bravely tried to intervene to stop the attack and their actions were very courageous.
“We are speaking to the families of those concerned and doing all we can to support them at this terrible time.
“We can now confirm that both the deceased were previously known to each other and there are no outstanding suspects.
“A man, who was the driver of a car, has been arrested and bailed for a very serious offence and we must carry out a full investigation, looking at all the circumstances.
“I would ask the media not to speculate on the causes of the deaths while we are awaiting the outcome of two post-mortems, it is important that we deal with facts.
“Lastly, we appreciate the support we have received from the public.
“A number of people have already come forward, but we are still asking for anyone who has not to make contact with us. Any information could be vital in helping us fully understand why this dreadful incident happened.”
Any witnesses or anyone with any information is asked to call police on 101 or contact via Twitter @MetCC. Please quote reference CAD 1496/24JAN.