[2][3][4][5] Sacoolas admitted that she had been driving the car on the wrong side of the road, and the police said that, based on CCTV footage, they believed that to be true.

Harry Dunn, a 19-year-old resident of Charlton near Banbury,[7] was riding his motorcycle on the B4031 road about 400 yards (370 m) from the exit of RAF Croughton on the evening of 27 August 2019, when he was struck by a car.

[18][19] An investigation into the collision led by Nick Adderley, the chief constable of Northamptonshire Police, determined, from CCTV records, that a car had been travelling on the wrong side of the road.

[22] On 14 September, Foreign Office diplomat Neil Holland texted a US official that "It's obviously not us approving of their departure", but that, since the US was not waiving immunity, "I think you should feel able to put them on the next flight out".

Furthermore, they contended, diplomatic immunity no longer applied upon Sacoolas's return to her home country; therefore, it would be possible to take civil action in the US courts.

If asked the US line was to say that Anne Sacoolas would not return to the UK, despite the previous intervention of Raab and the Prime Minister, Boris Johnson, which had included a call to the president.

"[39] On 15 October 2019 the Dunn family announced their intention to start a judicial review action into the advice given by the FCO to Northamptonshire Police regarding the diplomatic immunity of Anne Sacoolas and set up a CrowdJustice web page.

"[45][46] On 21 November, Dunn's parents expressed their disgust with Raab, who had defended the government's decision to seek legal costs.

[47] On 25 November Dunn's father, together with a group of more than 50 others, were, for fire safety reasons, prevented by staff from entering a hustings attended by Raab in East Molesey Methodist Church.

[48] Dunn's parents sought leave to bring a judicial review on 25 November, detailing the Foreign Secretary's actions over the extension of diplomatic immunity to intelligence staff and families at RAF Croughton.

"[49] The Archbishop of Canterbury Justin Welby wrote to the US ambassador in London early in October, asking that the extradition of Anne Sacoolas should not be blocked, but had at the time not received a reply.

[50] In December, Dunn's parents announced they were to file a civil lawsuit in Virginia, where Sacoolas lived, seeking to compel her to return to the UK.

Their lawyer referenced English common law which, they asserted, allowed offences committed in one country to be the subject of charges laid in another.

[52] In December 2019, the Crown Prosecution Service announced that Sacoolas was to be charged with causing death by dangerous driving and that it was starting extradition proceedings against her.

[58] The US State Department's initial response was "The use of an extradition treaty to attempt to return the spouse of a former diplomat by force would establish an extraordinarily troubling precedent" and that the request was "highly inappropriate".

[60] In January 2020 Northamptonshire Chief Constable Nick Adderley requested an urgent meeting with the commander of the military base after footage emerged of another vehicle on the wrong side of the road near RAF Croughton.

[61][62] Officers gave details of a separate crash, in October, in which a police vehicle had been struck by a car being driven on the wrong side of the road.

[69][70] An adjournment debate on RAF Croughton, in the House of Commons, was led by local Member of Parliament Andrea Leadsom, who focused on Dunn's death and called for the government to intervene and block plans to modify the airbase.

[71] As of August Suella Braverman, the Attorney General for England and Wales, was considering trying Sacoolas in absentia on a charge of causing death by dangerous driving.

[72] The prospect of a virtual trial, an option being considered by the attorney general, received support from the prime minister, Boris Johnson.

"[79] On 16 February 2021 Ellis ruled that Dunn's family would be able to sue Sacoolas for damages, dismissing her argument that holding the proceedings in the UK would be "more convenient".

[9] In March 2021, Sacoolas's lawyer Amy Jeffress said that, since the charge pending in Britain against her would not usually result in a prison sentence in the US, her client was not inclined to return to the UK to face trial.

Jeffress also rejected claims that Sacoolas had not sought assistance, saying she that she had stopped a passing driver and asked them to call for an ambulance, while she had contacted police at RAF Croughton.

[86] On 22 March 2022 MP Andrea Leadsom, raised a topical question in Parliament to ask the Secretary of State Dominic Raab to give an update on what was being done to deliver justice.

[89][90] On 20 October 2022, the Old Bailey heard and accepted Sacoolas's plea of guilty (via video link) to the charge of causing death by careless driving.

"[94] On 21 October 2019 the British Foreign Secretary, Dominic Raab, claimed that according to "arrangements" agreed upon by the US and the UK in 1995, the spouses and children of US intelligence officers at RAF Croughton were considered part of the US embassy and thus eligible for diplomatic immunity under the terms of the Vienna Convention, even though the officers themselves were deemed ineligible to claim diplomatic immunity for criminal behaviour outside the base.

[97] On 22 July 2020 it was widely reported that the UK and US governments had agreed to close the "loophole" in the arrangement that allegedly provided immunity from criminal prosecution for the family of US staff (though not retroactively).

[13][100] In December 2022, Dunn's family welcomed major changes to road safety outside US bases in the UK, announced in a letter to them from the Transport Secretary.

[102] In December 2023, Dunn's family said that something had gone "very badly wrong" after another US citizen had been able to evade British justice after alleged involvement in a road accident.

He noted remarks, made by Conservative MP David Mellor in 1983, who claimed 2,000 US servicemen had been convicted for traffic offences in the previous year.