The grieving newlywed campaigned for legal changes – named Harper’s Law – which has extended mandatory life sentences to anyone who commits the manslaughter of an emergency worker on duty.
Harper’s Law, which came into force in the summer, happened because she lobbied the Government after being “outraged” by the prison sentences handed to the three teenagers responsible for killing her husband while he responded to a burglary.
It was just hours after he was due to clock off and begin his honeymoon.
In June when the changes became law, Mrs Harper told the PA news agency that it was a positive development, but said she feels she will “never be able to move on” from her husband’s death.
Mrs Harper said: “I will never be rid of the hollowness that the burden of grief inflicts, but I know without hesitation that my husband Andrew would be immensely proud of this achievement in his name.
“Andrew believed in fairness and peace – he had the strongest moral compass of anyone I ever met and that is why I know without a shadow of a doubt that he is smiling down at me with pride and love as Harper’s Law, his legacy, is now achieved.”
Pc Harper, 28, died from his injuries when he was caught in a strap attached to the back of a car and dragged down a winding country road as the trio fled the scene of a quad bike theft in Sulhamstead, Berkshire, on the night of August 15 2019.
Henry Long, 19, was sentenced to 16 years and 18-year-olds Jessie Cole and Albert Bowers were handed 13 years in custody over the manslaughter of the Thames Valley Police traffic officer.
Long, leader of the group, admitted manslaughter while passengers Cole and Bowers were convicted of manslaughter after a trial at the Old Bailey.
All three were cleared of murder by the jury.
Harper’s Law was among the new measures in the Police, Crime, Sentencing and Courts Act.
It is not be retrospective, meaning Pc Harper’s killers cannot have their sentences extended.
The move extends mandatory life sentences to anyone who commits the manslaughter of an emergency worker on duty, including police, prison officers, firefighters and paramedics. Judges determine the minimum term someone handed a life sentence serves before they are deemed eligible for release.
There is scope for judges to deviate from this if they feel there are “truly exceptional circumstances”.
Speaking this year when the measures came into force, Mrs Harper said: “Almost three years ago my husband was robbed of his life and we were both robbed of our future together.
“Nothing will ever change that. This law will not change the outcome for his killers.
“But no longer will a family have to endure the pain of injustice in court as I did those many months ago – and that is a significantly powerful outcome.”
She added: “I know that many, many people will feel vindication at actually being able to believe in some legislation written in our history books.
“Throughout this journey I have met so many incredible people, fellow widows and widowers who know this unique pain I feel, as well as too many others who have lost loved ones in unspeakable ways and still have not seen any justice.
“I hope that this will help not only me but all of those who have experienced these cruel atrocities, we may never move on but we can try to move forward.”