Harry Dunn's family have hired one of Britain's top extradition lawyers in their bid to persuade the incoming US president, Joe Biden, to send his alleged killer back to the UK.
Nick Vamos, the former head of extradition and special crime at the Crown Prosecution Service (CPS), is to work pro bono for the Dunn family to help bring Anne Sacoolas to trial.
The lawyer, now a partner at Peters and Peters law firm, could also play a key part in any attempt to try Ms Sacoolas even if Mr Biden decides to stick with the Trump administration's refusal to accede to extradition or to lift her diplomatic immunity.
One option that may still be explored is the possibility of prosecuting Ms Sacoolas in absentia. The CPS has said it will continue to pursue the case despite the family's setbacks in their legal efforts to secure justice.
Mr Dunn, 19, died when his motorbike was hit by a car being driven on the wrong side of the road by Ms Sacoolas, an American, outside RAF Croughton in Northamptonshire on August 27 last year.
Ms Sacoolas, 43, was charged with causing the teenager's death by dangerous driving after the crash. But she was able to return to her home country after the US Government asserted diplomatic immunity on her behalf, sparking an international controversy.
Mr Vamos told The Telegraph: "There is an opportunity with the new administration in the US to invite them to finally do the right thing and not rely on a disputed claim of diplomatic immunity to allow Ms Sacoolas to avoid British justice."
He said there were options if she could not be returned to the UK but "the primary object is and always has been that she faces justice in the UK in person".
"Whilst there is an apparent stalemate where the CPS are unable to commence proceedings while she refuses to return either voluntarily or pursuant to extradition, there are further legal options we would like to explore with them," Mr Vamos added.
As the head of special crime at the CPS, Mr Vamos was responsible for cases including the prosecution in the Hillsborough disaster and the controversy over the Conservatives' election funding with the party's battle bus.
He was also responsible for masterminding new extradition rules after Theresa May refused a US request for Gary McKinnon to stand trial for the "biggest hack of all time" into 97 US military and NASA computers.