LONDON — A U.S. diplomat's wife accused of killing 19-year-old motorcyclist Harry Dunn while driving on the wrong side of a road in England has been charged with causing death by dangerous driving, authorities said Friday.

Anne Sacoolas, 42, flew back to the United States three weeks after the crash in August near RAF Croughton in Northamptonshire. The State Department has said Sacoolas is covered by diplomatic immunity and cannot be extradited.

Harry Dunn. Courtesy of the Dunn Family

The Crown Prosecution Service, which handles criminal cases in the United Kingdom, confirmed the charge Friday and said it had started an extradition process in order for her to return to the country and appear in court.

“Following the death of Harry Dunn in Northamptonshire, the Crown Prosecution Service has today authorized Northamptonshire Police to charge Anne Sacoolas with causing death by dangerous driving," Chief Crown Prosecutor Janine Smith said.

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The U.K. Home Office is responsible for making extradition requests and the decision may be ultimately up to Prime Minister Boris Johnson, who has previously called for Sacoolas to return to the U.K.

Britain's foreign minister Dominic Raab welcomed the charging decision. "I hope that Anne Sacoolas will now realize the right thing to do is to come back to the U.K. and cooperate with the criminal justice process," he said in a statement.

However, Sacoolas' lawyer Amy Jeffress said in the statement that her client "will not return voluntarily to the United Kingdom to face a potential jail sentence for what was a terrible but unintentional accident."

"A potential penalty of 14 years imprisonment is simply not a proportionate response," she said. "We have been in contact with the U.K. authorities about ways in which Anne could assist with preventing accidents like this from happening in the future, as well as her desire to honor Harry’s memory."

A U.S. Department of State spokesperson said the decision to press charges was not a "helpful development."

After offering their "deepest sympathies" to the Dunn family for their loss, they said: "We are disappointed by today’s announcement and fear that it will not bring a resolution closer.

They added that the U.S. had been clear that Sacoolas had diplomatic immunity at the time of the accident occurred and the U.K.'s foreign minister had "stated the same in Parliament."

Dunn's family has been campaigning for her to face justice and traveled to Washington, D.C., to make their case. They met President Donald Trump in October and were given what they called a "bombshell" offer to meet Sacoolas in the White House, which they declined.

"We set out so long ago and we believed and we believed, and we've done it, we've got the charge. It's amazing," Harry's father, Tim Dunn, told Sky News.