The parents of 19-year-old motorcyclist Harry Dunn, from Charlton near Banbury, have called on the US suspect in the case to return to the UK to face justice, saying: "It's the right thing to do."
Mr Dunn's mother, Charlotte Charles, and the teenager's father, Tim Dunn, told a press conference in New York that they felt let down by the decision to allow Anne Sacoolas - the motorist who allegedly collided with the teenager - to flee the country and return to America shortly after the crash outside RAF Croughton in Northamptonshire on August 27.
Charlotte Charles, (mother of Harry Dunn) speaking at a press conference in New York
The suspect, 42-year-old Mrs Sacoolas, has been said by the US to be covered by diplomatic immunity as the spouse of a US intelligence official, though that protection is now in dispute.
Mrs Sacoolas has offered to meet Mr Dunn's parents.
The family said CCTV evidence in the moments leading up to the crash made it "a clear-cut case".
A tearful Ms Charles told reporters: "We just want to know that she is being brought back to the UK."
You know, that would be a huge step in the right direction. It's the only right thing to do. It's the only humane thing to do. All of our grief has gone on hold, it's coming out in other horrific ways, your legs feel like lead, you're in pain morning until night that no painkillers can take away. You're not able to cry, because we can't understand this whole situation as to why she (Anne Sacoolas) would have left us without wanting to meet us back then. She needs to get on the plane and get back to the UK, just do the right thing. It shouldn't be that difficult, it shouldn't have been this difficult, she surely didn't have to go."
Ms Charles said the family have been told there is CCTV evidence showing Ms Sacoolas leaving the RAF base "on the wrong side of the road".
She added: "CCTV follows her all the way down the road on the wrong side of the road and you see Harry's headlight of his motorbike and then there is a big fireball when his bike went up."
"So it should have been a clear-cut case. It should have been simple and I promised Harry and we promised Harry as a family when we'd lost him that night, when we were talking to him in the hospital when we'd lost him already, that we would make sure justice was done."
The teenager's father also called on US President Donald Trump to act in an effort to secure justice for his son.
Mr Dunn said: "There's just no way I can start grieving yet, as a family we can't start, we need this resolved.
Somewhere, somebody has made a decision to give this lady immunity. On that night there was an accident, a lady made a mistake, she killed our son, she didn't mean to kill him, she didn't mean to have an accident, but you cannot walk away from that and just leave and expect nothing to happen. Our boy died and he deserves to have some justice. That's all we want. I would say to him (President Trump) as a man, as a father, how could you let this happen, if you are a father and your child died surely you'd want that person to own up and take responsibility for their action?
Speaking to the PA news agency following the press conference, Mr Dunn called on the suspect to "come out of hiding" and "set an example" to her own children.
He added: "Just get on the plane. Face up to what you have done, having left us seven weeks ago with what we have lost - this is 100 times, a hundred times harder than it needed to have been."
The family reiterated their hope to secure Ms Sacoolas a suspended sentence, rather than immediate custody, so as not to take her away from her family.
But they said their hopes of a meeting between the two parties should happen "in her own words, in a room, on our terms" back in the UK.