The killers of PC Andrew Harper will not have their sentences increased after judges rejected the attorney general's case that they were "unduly lenient".
Suella Braverman QC had argued Henry Long, Albert Bowers and Jessie Cole should be handed longer jail terms.
She said the sentences of the three men had caused "widespread public concern".
PC Harper died after he was dragged for more than a mile behind a car driven by Long, 19, in Berkshire in August 2019.
The Thames Valley Police officer became tangled in a strap attached to the back of the car as he tried to apprehend the teenagers, who were suspected of stealing a quad bike.
Following a trial at the Old Bailey, Long, Bowers and Cole were all cleared of murder but convicted of manslaughter.
Long was jailed for 16 years, while getaway car passengers Bowers and Cole, both 18, were sentenced to 13 years each.
Dame Victoria Sharp said at the hearing earlier that their applications to reduce their sentences had also been refused.
Cole and Bowers launched separate appeals against their convictions for manslaughter, which were also rejected.
Following the judgement, a spokesman for the attorney general said she believed the sentences should be increased, but "respects the decision of the Court of Appeal".
PC Harper, 28, from Wallingford, Oxfordshire, had been married to his wife Lissie for four weeks when he died.
Mrs Harper, 29, said in a statement she was "disappointed" and the sentences "do not reflect the severity and barbarity of the crimes they committed".
"I continue to feel let down by our justice system and the inadequate laws that we have in place," she said.
Mrs Harper has been campaigning for a change to the law to increase the sentences of those who kill emergency services workers.
In their judgement, Dame Victoria Sharp, Lord Justice Holroyde and Mr Justice William Davis said PC Harper's family had the "profound sympathy of the nation".
They said "no one" doubted the "seriousness of the offending in this case", the "importance of the fact that the victim was a police officer engaged in performing his duty" and the "gravity of the harm caused".
But they added that trial judge Mr Justice Edis "had to sentence three young offenders for manslaughter, not for murder" and that "mere disagreement with his 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 judges said the attorney general's argument, that the sentences of Bowers and Cole were unduly lenient because the judge did not "depart" from the sentencing guidelines, was "to say the least, an unusual submission".