Video report by ITV News Correspondent Stacey Foster
Northamptonshire Police have confirmed officers will go to the US to interview the woman who claimed diplomatic immunity following her involvement in the crash that killed Harry Dunn.
Speaking during a press conference, Nick Adderley, chief constable of Northamptonshire Police, said the suspect had asked to be interviewed by UK police officers in the United States under caution.
The 19-year-old motorcyclist died when his bike crashed into a car driven by Anne Sacoolas outside RAF Croughton in Northamptonshire on August 27.
Ms Sacoolas' husband was reportedly stationed at the base as an intelligence officer.
Mr Adderley said: "Lawyers have clearly stated that the suspect wants to be personally interviewed by officers from Northamptonshire Police in order for them to see her and the devastation this has caused her and her family.
"She did not want to provide a pre-prepared statement which is her right to do so. We do understand from colleagues in the US that the family is utterly devastated."
He added that the force were awaiting the necessary visas before officers could travel to the US, but that the suspect would be interviewed under caution once that could take place.
Mr Adderley also called on Radd Seiger, spokesman for Harry Dunn's family, to "exercise constraint".
He said: "I urge the family spokesman to exercise constraint in his commentary as the case moves forward. I understand the emotion and I understand the anxiety."
In a statement earlier in October, Ms Sacoolas expressed her "deepest sympathy" to the Dunn family and said she spoke to authorities at the scene of the crash.
Her statement read: "She spoke with authorities at the scene of the accident and met with the Northampton police at her home the following day. She will continue to cooperate with the investigation.
"Anne would like to meet with Mr. Dunn’s parents so that she can express her deepest sympathies and apologies for this tragic accident."
Mr Dunn's family said earlier they were "perplexed" by the news UK police were heading to the US to continue the investigation into their son's death.
They added they believed the Crown Prosecution Service (CPS) had a police file on the case, and thought they were waiting on a decision over charges and if extradition proceedings would begin.
Mr Seiger said on Twitter: “Yesterday the family were told the police had passed their file to the CPS (Crown Prosecution Service) yet tonight were informed that the police were travelling to the USA to interview Mrs Sacoolas.
“Those two statements appear to be contradictory on the face of it, further compounding the family’s misery.”
Harry’s parents, Charlotte Charles and Tim Dunn, will on Tuesday meet with shadow foreign secretary Emily Thornberry, who is expected to call for a Parliamentary inquiry into the teenager’s death.
On Monday, Foreign Secretary Dominic Raab told the Commons he had commissioned a review into immunity arrangements for US personnel and their families at the RAF Croughton annex in light of the case.
Mr Raab said there are “no barriers to justice being done” for Harry.
He also said the UK Government believes diplomatic immunity “clearly ended” for Mrs Sacoolas, 42, when she left the country for America shortly after the crash.
He added it would be for the CPS and police to decide what steps to take, telling MPs he is “not aware of any obstacle” under the UK/US Extradition Treaty.
Harry’s parents have cancelled a meeting set for Wednesday afternoon with Chief Constable Nick Adderley of Northamptonshire Police after it became clear his intention was not to answer “a series of key questions” the family had prepared, Mr Seiger said.
Announcing the decision to cancel the meeting on Twitter, Mr Seiger said: “The time for condolences has long since passed and the answers to the many questions about Anne Sacoolas’s departure and next steps are long overdue!
“Every moment that passes without those answers only compounds the family’s pain and misery.
Responding to this on Tuesday in the press conference, Mr Adderley said: "I have offered to go and see the family on two occasions now and on both occasions that has not been able to happen.
"The reason for that not taking place is because the information being asked for by the spokesman - who is not their lawyer, by the way - I legally cannot provide."
Mrs Charles and Mr Dunn travelled to the US last week in an attempt to put pressure on authorities to return Mrs Sacoolas to the UK.
The visit included talks at the White House with President Donald Trump, during which the family was told that Mr Dunn’s alleged killer was in a nearby room and prepared to meet them.