A police officer died when he was dragged for more than a mile by a car along a country lane, a court heard.
The Old Bailey was told distressing details of how Andrew Harper got caught in a towing strap trailing behind a car that was trying to evade him.
His uniform was “ripped and stripped from his body” and he was “swung from side to side like a pendulum”.
Henry Long, 18, of Mortimer, Reading, and two 17-year-old boys deny murdering the 28-year-old in August 2019.
Brian Altman QC, prosecuting, said Mr Long was driving when PC Harper, from Wallingford, Oxfordshire, suffered “the most awful injuries”.
PC Harper and a colleague were responding to a report of a quad bike theft near Sulhamstead, Berkshire, when he was “lassoed around his ankles by the loop of the strap”, Mr Altman said.
Mr Long “floored” the car, driving at an average speed of 42.5mph, with the policeman “shackled behind” the vehicle, the court heard.
PC Harper was “swung from side to side like a pendulum in an effort to dislodge him, losing items of his police uniform along the way, with the rest of his uniform being quite literally ripped and stripped from his body,” Mr Altman said.
“He died totally naked apart from his socks and boots and some shredded remnants of the trousers he was wearing.”
Mr Altman said: “It is the prosecution case that Long drove that car knowing full well that PC Harper was entangled in the strap, and he drove it in a manner calculated to dislodge him, and make good their escape, as had been their plan all along.”
PC Harper was barely alive when he was found by his colleague, and had suffered “absolutely catastrophic, unsurvivable injuries”, he said.
Mr Altman said PC Harper and PC Andrew Shaw were “well beyond the end of their shift” when they decided to attend the call about the quad bike theft.
“It was a decision that was to cost Andrew Harper his life,” he said.
They pair entered a “rural, unclassified single carriageway road”, where they “chanced upon” a Seat Toledo towing the bike, the court heard.
The bike had been attached to the hinge of the car’s boot by a “crane strap” wound around the bike’s handlebars.
‘Lassoed around ankles’
Mr Altman said after the unmarked police car and the Seat met, the defendant on the quad bike dismounted, unhitched the bike, and tried but failed to get inside the Seat.
The court heard that he “bolted” along the driver’s side of the police BMW towards the Seat which had “rounded the police car, so that the cars were now boot to boot”.
Mr Altman said “almost simultaneously” PC Harper got out of the police vehicle and began to run behind it to intercept him.
He added: “In his rush to ensure that he and his friends did not get caught, the defendant, who had unhitched the crane strap…. had been unable to replace the crane strap in the car boot.”
The court heard PC Harper did not realise where the strap was and stepped with both feet “into the loop made on the road surface”.
Mr Altman said as Mr Long “floored” the Seat to escape, PC Harper was “lassoed around his ankles by the loop of the strap”.
Mr Altman asked: “If Long and his friends had no idea that Andrew was entangled in the strap, why was there a need to drive so recklessly?
“The answer is easy to see. All three knew it was a police car that had confronted them.”
‘Screaming and shouting’
He dismissed claims that the defendants were unaware PC Harper had become entangled in the strap as “ludicrous”.
“It’s not difficult to imagine the screaming and shouting that must have taken place inside that car about what was unfolding,” he said.
Jurors were told the car left a “snaking trail” of tyre marks, blood and clothing as it swerved across the lane.
As the Seat crossed the A4 with PC Harper still “shackled behind” it another driver who slammed on his brakes thought there was a “bloodied deer attached to the car”.
Mr Altman said the three defendants were arrested later the same night at a traveller caravan site.
The court heard Peter Wallis, who lived in Bradfield Southend, called the police at 23:17 BST after seeing masked men “make off” with his new Honda TRX500 quad bike.
Earlier in the day, the court heard, Mr Wallis had seen a car with four balaclava-clad men inside pull up outside his house.
He said two ran in the direction of the £10,000 quad bike, and replied “aggressively” when confronted.
‘Scary and intimidating’
Later that night, Mr Wallis said, he was woken up by a car’s headlights, and saw the defendants fixing the 330kg (661lb) bike to their car with the crane strap.
When the car was searched, police found three crowbars, a large axe, a pair of choppers, a hammer and a pipe.
Mr Altman suggested the items were to be used by the defendants as weapons “if anyone stood in their way”.
“Constable Harper did try to stand in their way, and he paid the ultimate price for it,” he said.
Mr Long has previously admitted manslaughter and conspiracy to steal a quad bike.
On Monday, the two 17-year-olds, who cannot be named due to their age, pleaded guilty to conspiracy to steal a quad bike. The pair also deny manslaughter.
The, trial, due to last six weeks, continues.