Far right fanatic Thomas Mair has been handed a whole life term for murdering the Labour MP in what prosecutors called an "act of terrorism".
Mrs Cox was stabbed 15 times and shot outside her constituency office in Birstall, West Yorkshire.
The former assistant to Jo Cox has recalled the moment the MP was shot and stabbed to death in her West Yorkshire constituency.
Giving evidence at her murder trial, Fazila Aswat said she had tried to encourage Mrs Cox to think of her two children as she lay injured in her arms.
Describing the moment she pulled up in a silver Vauxhall Astra with Mrs Cox and another colleague outside the library in Birstall, West Yorkshire, she said: "I got out of the car. I was still on the roadside. Jo walked over to the side of the pavement and my colleague walked a few steps closer up. In that instant our lives changed forever.
"The next thing I saw was Jo on the floor and there is a man stood over her with a knife and I think that's when I knew it was completely wrong. At that time - panic. I started to shout 'somebody help, help'.
"There was a gun, there was a knife and she was on the floor. I can remember the movement, it was really fast so I can't say which part of the body was targeted."
Mrs Aswat said that she had told the MP to run away between attacks but Mrs Cox replied: "Fazila, I can't run, I'm hurt."
Thomas Mair, 53, denies her murder.
She may have only served her constituents for little more than a year, but those whose lives Jo Cox touched won't forget her lasting legacy.
Thomas Mair is being described as an extremist, a fanatic, an assassin – even ‘a constituent’. But make no mistake – he is a terrorist.
Thomas Mair "betrayed the quintessence of our country" in the senseless killing of MP Jo Cox, the judge said.