The parents of a teenage motorcyclist killed in a crash have said they are considering civil action against a US diplomat's wife suspected of driving the other vehicle.
Harry Dunn, 19, died in a crash with a Volvo in Northamptonshire on 27 August.
Suspect Anne Sacoolas later left the UK despite telling police she had no such plans.
Mr Dunn's father Tim said the family had "heard nothing" since meeting Foreign Secretary Dominic Raab.
He said they were also "still waiting" for information from the US government following President Donald Trump's comments.
On Wednesday, the president said his administration would speak to Mrs Sacoolas "very shortly and see if we can do something where they meet".
But a briefing note held by Mr Trump at the press conference said Mrs Sacoolas would not be returning to the UK after being granted diplomatic immunity.
Mr Dunn's mother Charlotte Charles said the US's apparent approach was "beyond any realm of human thinking".
The family is still planning to go to the US.
Tim Dunn said: "We have to go to America and speak to the American people. We can't let this be swept under the carpet."
He said they had taken legal advice on civil action and it was "an avenue we are looking at".
"We are out of our depth really, I feel like I'm on autopilot," he added.
What is civil action?
In a civil case a complaint is made by a person or company in a law court against another person or company said to have done something to harm them.
This is commonly referred to as being sued.
The case is then dealt with by a judge, who determines whether the defendant has liability for causing the harm.
The outcome can differ depending from which country the case is brought, but the if the defendant is found to be liable they often have to pay compensation in the form of damages.
However, diplomatic immunity extends to civil cases.
Prof Craig Barker, dean of the School of Law and Social Sciences at London South Bank University, said the couple "could pursue action in the US".
He explained that the diplomatic immunity for civil cases only extends to the "receiving state", in this case the UK.
But Prof Barker said the family "would need to find a court in the US to accept the case," which he said would be costly and given the US stance may be difficult.
He also said there could be a claim made against the US Government in the UK, but a case like that had never been tested in court.
After speaking to Mr Raab on Wednesday, as well as their local MP and Business Secretary Andrea Leadsom, Mr Dunn said the family felt "we've exhausted our governments efforts".
The teenager's parents described the meeting with Mr Raab as a "publicity stunt".
Afterwards Mr Raab said the justice process was "not being allowed to properly run its course".
Chief Constable of Northamptonshire Police Nick Adderley said the investigation into the crash was "carrying on".
"We are expediting that file, so that file of evidence will be with the Crown Prosecution Service within the next few days," he said.
He added the force was exploring "nuances" within diplomatic immunity in the hope of bringing Mrs Sacoolas back to the UK.
South Northamptonshire Council said along with Northamptonshire County Council it had put up new signs around RAF Croughton making clear which side of the road to drive on.
Mr Dunn has welcomed the idea of speaking with Mrs Sacoolas.
"We want answers from her about what happened, there are things the police cannot answer," he said.
Police have said CCTV of the crash in which the teenager died shows a Volvo travelling on the wrong side of the road.
Speaking at the press briefing on Wednesday - after his conversation with Prime Minister Boris Johnson - Mr Trump said: "The woman was driving on the wrong side of the road, and that can happen.
"You know, those are the opposite roads, that happens. I won't say it ever happened to me, but it did.
"So a young man was killed, the person that was driving the automobile has diplomatic immunity, we're going to speak to her very shortly and see if we can do something where they meet."
Speaking in Northampton on Thursday, Labour leader Jeremy Corbyn said Mr Trump's comments were "crass and insensitive".
He also said the use of diplomatic immunity in the case was "completely unacceptable", and that more pressure should be put the US to return Mrs Sacoolas to the UK.
The crash in which Mr Dunn died happened close to RAF Croughton, a US Air Force communications station, where Mrs Sacoolas's husband Jonathan had been working.
Number 10 said the prime minister had urged Mr Trump to reconsider the decision to allow Mrs Sacoolas immunity in order that "the individual involved can return to the UK, co-operate with police and allow Harry's family to receive justice".