Face of Nation : Aliny Godinho was attacked by her estranged husband as she went to collect her children from school in Surrey, Guildford Crown Court heard.
Toni Miller was one of three women who saw the attack.
Ricardo Godinho has admitted manslaughter but denies murder and possessing an offensive weapon.
Jurors heard Ms Godinho and Mrs Miller – along with Rebecca Dyer and Natasha Carr – had just got off a bus on London Road, in Stoneleigh near Epsom.
Mrs Miller told the court she heard a “sharp scream” from behind and turned to see Mrs Godinho being attacked by a man.
“The scream sounded more like urgency or someone was in danger,” she said.
“I looked at her face and she was absolutely terrified. He made contact with her and pushed her daughter in my direction.
“She turned round to face the man and he grabbed hold of her and then when he pulled back I could see the blade of the knife.”
“I thought it was a Halloween prop, thought it was a joke. Aliny put up her arms to protect her and he started to stab her with the knife,” she added.
“He did not say a word. He was extremely calm and collected.”
Mrs Miller told the court she estimated Mrs Godinho was stabbed “six or seven times” before falling to the ground.
“As he let go, he looked up at their daughter and at that point I thought he was going to go for the child,” she said.
“The daughter turned to me and said ‘mummy is not coming back’,” she added.
Another mother, Natasha Carr, told jurors Mr Godinho made “quite quick jabs” into the side of Mrs Godinho’s torso and neck.
“There were a few screams after the first few stabbings and then she became quite lifeless,” she said.
“My first thought was that it was a terror attack or a psychopath.
“There was no expression on his face. No rage, very calm and collected. It seemed like he was doing a job.”
Jurors heard also heard from a third mother who witnessed the attack – Rebecca Dyer.
Mr Godinho’s defence barrister, Tom Little QC, told jurors Mrs Dyer was closest to the attack.
“In your police statement you said ‘the man did not acknowledge the presence of the little girl. It was as if she was not there,” he said, adding: “Would you say the focus was on Aliny?”
Mrs Dyer replied: “Yes”.
A fourth witness, Jodie Tamila, had been driving on the other side of the road and told jurors she saw Mr Godinho “run after a woman”.
“He was looking down at her. Stabbing her very violently, like in a horror film,” she added.
