On 15 August 2019, three irresponsible young men - Henry Long, Albert Bowers, Jessie Cole - stole a quad bike. It was a planned theft and something they did frequently. The quad bike was towed away from its owner's property. When confronted by the Police they implemented their escape plan. This required them to disconnect the tow loop from the quad bike and to drive away at speed as soon as all of them were in the car. As they drove away, PC Harper was caught up by the loop which was still attached to the car. He was dragged at high speed over a considerable distance and killed as a result.
Long, Bowers and Cole were charged with murder and stood trial at the Old Bailey before Mr Justice Edis and a jury. The prosecutionpresented a strong case and undoubtedly hoped for a guilty of murder verdict. Ultimately, the jury convicted Bowers and Cole of manslaughter. Long had already pleaded guilty to manslaughter at a pre-trial hearing in January 2020 and was entitled to a 25% discount from his sentence.
All three received custodial sentences and those are explained in the judge's sentencing remarks - LONG BOWERS COLE AND KING sentencing remarks FINAL.doc (judiciary.uk).
Even for those who have spent much time both in and observing the criminal courts, the ITV programme, presented by Sir Trevor McDonald, was particularly moving. The dignity and perseverance of PC Harper's widow stands in marked contrast to the disgraceful and disrespectful behaviour of the defendants during the trial.
The sentences were widely seen by the public as inadequate and the Attorney General referred the matter to the Court of Appeal but that court held that the sentences were not unduly lenient - R-v-Long-Bowes-Cole-Summary.pdf. The Court of Appeal stated that - "Mere disagreement with ... decisions as to the nature and length of the appropriate sentences provides neither a ground for finding the sentencing to have been unduly lenient nor a ground for finding a sentence to have been wrong in principle or manifestly excessive. The essential issue in each of the applications is whether the judge passed a sentence which was outside the range properly open to him in all the circumstances."
As a result of the campaign by PC Harper's family, the government announced in November 2021 that it would bring forward legislation to amend the law - Government to introduce 'Harper’s Law' - GOV.UK (www.gov.uk)
The outcome is Clause 3 of the Police, Crime, Sentencing and Courts Bill. The amendment to the law requires a life sentence under section 250 of the Sentencing Code for manslaughter of the type committed by Long, Bowers and Cole. However, such a sentence need not be imposed if the court is of the opinion that there are exceptional circumstances which which - (a) relate to the offence or the offender, and (b)justify not doing so. The exceptional circumstances provision is probably not what some campaigners hoped for but it was inevitable that legislators would fall shy of imposing a life sentence regardless of all circumstances.
The Bill is currently in its final throes of the parliamentary process and Royal Assent can be expected in the near future.
The general leniency of the law toward even serious offenders under age 25 will continue to be a matter of concern to the public and to their victims - Law and Lawyers: PC Harper ~ manslaughter ~ sentencing, undue leniency, retrials, young adults (obiterj.blogspot.com)
In Clarke, Andrews and Thompson  EWCA Crim 185 the Lord Chief Justice set out the modern approach to the sentencing of those who are legally adult (18 and over) but under the age of about 25.
There have been calls for a separate, but not necessarily more punitive, sentencing guideline for young adults (18-25) - Howard League for Penal Reform 2018 -‘Sentencing Young Adults - Making the case for sentencing principles for young adults. The Howard League report is discussed at Youth Justice Legal Centre - A report on sentencing young adults.
Further material is in this July 2011 report by Criminal Justice Alliance: Sentencing Young Adults: Getting it Right
Scotland has recently introduced sentencing guidelines reforms placing the emphasis more on rehabilitation - Scottish Sentencing Council News
16 March 2022