Henry Long, 19, and Jessie Cole and Albert Bowers, both 18, had denied murder. Long admitted manslaughter and his co-accused were found guilty of the same offence by a jury at the Old Bailey in central London last week.
There were tears and gasps from some people in the public gallery as Long was sentenced to 16 years in prison, and Bowers and Cole handed jail terms of 13 years each.
The defendants reacted to their punishments: Long looked up briefly to glance at members of his family, Cole kept his head bowed and Bowers appeared shocked.
PC Harper was dragged for a mile behind their car, after he tried to stop the group towing away a quad bike, stolen from outside a house in Berkshire in August last year.
The judge, Mr Justice Edis, said on Friday his role was to impose a sentence against the teenagers responsible for PC Harper’s death which reflected “the seriousness of this case and protects the public”.
Passing sentence, the judge said Long was “dangerous” and had described the events as “just an ordinary police chase”.
He described the killers as “young, unintelligent but professional criminals”, and said none of them had “shown anything resembling remorse”.
“You killed a talented and brave young police officer who was going above and beyond his duty in order to provide a public service,” he told them.
“You did so because you have deliberately decided to expose any police officer that got in your way to a risk of death.”
The 28-year-old Thames Valley police officer’s grieving widow, Lissie Harper, said she was “utterly shocked and appalled” at the decision not to convict the trio of murder.
Reading out her victim impact statement, she described to the court the “indescribable trauma” of being “robbed” of a future with her “soulmate”, and finding herself in “a lost and endless world” following her husband’s death.
“They took more than one life away that day, they stole the person I used to be.
“I am now a shadow of the person I once was. Broken, distraught, beaten, a void, an empty shell.”
Deborah Adlam, PC Harper’s mother, added in her victim impact statement: “I have sat in the mortuary of my son’s covered body, too damaged for me to see. He was our first-born child and he has been ripped from me.”
© 2020 Sky UK
News – PC Harper killing: Three teenagers jailed over police officer’s death