Here is a timeline of events which surrounding the death of PC Andrew Harper:

Thursday August 15 2019

4.50pm: Henry Long, Albert Bowers, Jessie Cole and a fourth man, Thomas King, who is not a defendant in the trial, arrive at the home of Peter Wallis in Bradfield Southend, Berkshire, to steal his £10,000 quad bike. They are confronted by Mr Wallis and leave empty-handed.

READ MORE: Court hears from witnesses in Pc Andrew Harper trial at The Old Bailey

11.10pm: Long, Bowers and Cole return to Mr Wallis's house and, over 15 minutes, steal his quad bike. It is attached to a Seat Toledo by a strap and ridden by Cole.

11.17pm: Mr Wallis makes a 999 call to report a theft in progress. He says: "I've got four masked men outside my house and they've got weapons."

PC Harper and his crew mate PC Andrew Shaw are on the M4 in a BMW car.

11.28pm: The officers get a first glimpse of the Seat headlights approaching their car in Admoor Lane. The vehicles stop, facing each other around 5 metres apart.

Eight seconds later, Long mounts the verge as he drives around the police car. Cole is on foot behind the Seat. Having unhitched the quad bike, he tries to get back in the Seat.

Cole runs past the police car, pursued by PC Harper, and dives through the Seat passenger window, the Old Bailey is told.

PC Harper almost reaches the car and Cole but runs into the loop of the strapping trailing from the boot. He is dragged away as Long accelerates off, jurors are told.

The whole incident takes around 30 seconds.

11.29pm: Over a minute after PC Harper's disappearance, Pc Shaw - looking for his colleague - stops to recover Pc Harper's stab vest, which is in the road.

READ MORE: PC Andrew Harper murder accused said he 'watched Fast and Furious' on night of killing, court told

11.30pm: PC Harper's body is found by PC Christopher Bushnell in Ufton Lane. He has been dragged just over a mile for 91 seconds before he is dislodged on the other side of the A4. It means Long has driven at an average speed of 42.5mph, the court is told.

Pc Bushnell alerts his colleague PC Andy Kemp to the figure in the road and sets off in pursuit of the Seat.

Meanwhile, the National Police Air Service (NPAS) helicopter, is directed to the nearby Four Houses Corner travellers' site in search of the suspects.

11.31pm: Pc Shaw reaches the A4 and Ufton Lane where he finds his colleague

Meanwhile, Long heads towards Ufton Court but gets stuck behind a wedding coach and turns back, forcing Pc Bushnell to take evasive action to avoid a head-on collision, the court is told.

The Seat is then driven at speed towards Four Houses Corner and PC Bushnell loses sight, jurors hear.

11.42pm: The NPAS helicopter reports seeing, using thermal imaging, the apparently abandoned "very, very hot" Seat on the site with people standing around another car in an adjacent plot.

11.45pm: Pc Harper is pronounced dead in the road where he was found.

August 16 2019: The defendants are arrested in the early hours.

February 2020: Long, 19, and Cole and Bowers, both aged 18, go on trial at the Old Bailey for murder.

March 2020: The trial is abandoned due to the coronavirus pandemic.

June 2020: A retrial gets underway. The defendants deny murder but have admitted conspiracy to steal the quad bike. Long has admitted manslaughter.

The trial continues.