AN expert who created a reconstruction of PC Andrew Harper's final journey said 'it should have been obvious' to a driver that he was dragging the police officer's body behind his car.

Collisions specialist Simon Hall told the Old Bailey how he carried out a series of reconstructions along Lambden's Hill near Sulhamstead in Berkshire following the death of 28-year-old PC Harper when he responded to the alleged theft of a quad bike late on August 15, 2019.

PC Harper got caught in a looped strap between a Seat Toledo and the quad bike, and was towed for over a mile along the narrow country lane at an average speed of 42.5mph before coming free.

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PC Harper was barely alive when he was found by his crew mate, and had suffered 'absolutely catastrophic, unsurvivable injuries', the court heard previously.

Driver Henry Long, 18, from Mortimer, Reading, and two 17-year-olds who cannot be named for legal reasons all deny murdering the Thames Valley Police officer.

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Court artist's sketch of Henry Long at the Old Bailey. Picture: Elisabeth Cook/ PA

They all admit conspiring to steal a quad bike, and Long has admitted manslaughter, which the younger boys deny.

Mr Hall carried out a reconstruction using a 1.8m tall mannequin, weighing 90kg and with the dexterity of a human body.

He said: "It is my opinion that anyone driving the Seat could not fail to be aware that something of significant weight was being dragged behind the vehicle.

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"The drag effect on both the steering and handling of the car, and most significantly the noise of the mannequin being dragged along the road, meant that its presence behind the vehicle was clear and obvious."

Describing his experiences in the Seat – the exact vehicle involved on the night of PC Harper's death – Mr Hall said: "As soon as the run commenced it was immediately obvious to me that the mannequin was attached to the rear of the vehicle.

"Both the drag of the mannequin on the road and the noise of its movement was significant.

Oxford Mail:

A screen grab from the dashcam in PC Andrew Harper's car, showing the car being driven by Henry Long around the squad car, and one of the two 17-year-olds running to get back in it.

"When my speed fluctuated the lag and re-engagement of the tow-line was obvious to me as the driver.

"When I began to negotiate the bends, the pendulum effect of the mannequin being swung side to side was clearly and obviously detectable, both audibly and through its effect on the steering.

"I could hear the sound one side then hear it swooshing back again."

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His report from the reconstruction, read in court, stated "it should have been obvious" to the driver that something was attached to the vehicle.

He added: "In my opinion, the Seat was at times being steered vigorously from side to side to dislodge whatever the driver perceived was being dragged by the car."

Mr Hall described the road as a 'minor country road', around 3.4 metres wide (11.2ft), and with a road surface of granite chippings.

Oxford Mail:

Police helicopter footage of the caravan park which Long and the two 17-year-olds drove back to.

Asked by prosecutor Brian Altman QC about whether it was possible to drive at the 60mph speed limit, Mr Hall said: "You could drive it, but I wouldn't advise it.

"Certainly on the bendy sections, it would be very difficult.

"On the corners you couldn't see if anything was coming the other way."

One witness mistakenly thought he had seen a bloodied deer attached to the car before realising it was a man being dragged along, the court was told.

The trial was adjourned until Monday morning.