Dunn's mother to diplomat's wife: 'Just do the right thing'

Dunn, 19, died in August after a collision near RAF Croughton, an air force base in Northamptonshire, central England, that is used by the United States.

The American woman involved in the crash, Anne Sacoolas, later left Britain, invoking diplomatic immunity.

Harry Dunn's parents Tim Dunn and Charlotte Charles are lobbying to have the woman's immunity revoked and for her to return to Britain to face an investigation.

The UK Foreign Secretary reportedly said on Sunday that the diplomatic immunity of Sacoolas "is no longer pertinent."