Three teenagers have been found guilty of the manslaughter of PC Andrew Harper, who died after being dragged along a road by a car.
PC Harper died from catastrophic injuries after his ankles got caught in a strap trailing behind a vehicle driven by Henry Long, in August 2019.
Long, 19, had earlier admitted manslaughter but was cleared of murder.
Albert Bowers and Jessie Cole, both 18, were cleared of murder but found guilty at the Old Bailey of manslaughter.
Following their convictions, it can now be revealed jurors in the trial had to be given special protection after police received intelligence associates of the killers had planned to intimidate them.
PC Harper was dragged for more than a mile along country lanes in Berkshire after he and a colleague responded to reports of a quad bike theft, jurors heard.
The 28-year-old newlywed became “lassoed” to the back of a Seat Toledo after he “unwittingly” stepped with both feet into the loop of a tow rope as he tried to apprehend one of the defendants.
Prosecutors said the Abingdon-based roads policing officer was “swung from side to side like a pendulum” after Long sped off to escape the scene.
The court heard the Seat travelled for more than a mile towards the A4 before PC Harper became detached and died in the road.
Jonathan Laidlaw QC previously told jurors the defendants were prepared to use force “if met with resistance”.
The trio had a large axe, three crowbars and a hammer and were “plainly determined to steal the quad bike” from a home near Stanford Dingley, Mr Laidlaw said.
It was clear they were “intending, if met with resistance, that serious harm would be caused to commit the offence of theft or to secure their escape”, the court heard.
The defendants are due to be sentenced next Friday.
The officer, from Wallingford, Oxfordshire, had been married for just four weeks to his childhood sweetheart Lissie, before his death.
Within weeks, he and his wife had been due to honeymoon in the Maldives.
Long, from College Piece, Mortimer, Reading, pleaded guilty to manslaughter but denied murder along with Bowers and Cole.
Cole, of Paices Hill near Reading, Bowers, of Moat Close, Bramley, and Long all admitted conspiracy to steal a quad bike.