• Words by ITV News Washington Editor Alex Chandler

The house is dressed up for an all-American Christmas - candy canes along the driveway, twinkling lights and holly - a clapboard home in a quiet residential street.

In the driveway, returning from the school run, is Anne Sacoolas, the woman who had collided with British teenager, Harry Dunn last August, as she drove out of an airbase in Northamptonshire apparently on the wrong side of the road near where her diplomat husband was stationed.

Mrs Sacoolas left Britain days after the accident, claiming diplomatic immunity, leaving Harry's grieving family with many unanswered questions.

I wanted to know if she would speak to me about the accident, perhaps indicate if she would voluntarily return to the UK to help with the investigation.

"No, no," she said as she reversed out of the driveway. There were no words of regret, no apology, nor any explanation as to why she had left Britain and refused to return.

  • Video report by ITV News Washington Correspondent Robert Moore

Harry Dunn's parents watched in silence as we played to them the footage of Anne Sacoolas, filmed that very morning.

Harry's mother Charlotte Charles sat concentrating on the images, tears streaming down her cheeks.

It was clearly a deeply distressing experience for her. She told me she hadn't expected to feel so upset but the pictures just floored her.

I asked her for her reaction: "Distraught, to be honest," she replied, speaking through her tears.

Ms Charles added: "She's clearly going about her normal day, driving and taking kids to school.

"She looks well, she looks calm, the house is all decorated for Christmas stuff, with candy canes on driveway, the lights around the tree."

Harry's mother Charlotte Charles sat concentrating on the images, tears streaming down her cheeks. Credit: ITV News

Ms Charles continued: "She's going about what she would normally do, as if nothing has ever happened.

"Her life looks so normal, and she has completely wrecked ours."

"We've been giving her the benefit of the doubt all along, and we didn't want to think she was getting on with her life... She clearly is and it hurts like hell."

Harry's father, Tim, was just as shocked by our footage.

He said: "She's got to come back now, there's no shadow of a doubt, she must come back and answer for what she has done.

"Got to...can't see how any immunity of any kind, or any such rubbish by a government, can give someone the free license to kill someone by accident and just walk away from it. This can't happen."

The family came to Washington to press for Mrs Sacoolas to return to the UK, but as yet the calls remain unanswered.

To see video of Anne Sacoolas was yet another desperately difficult stage in their fight for Harry.