A pioneering CCTV and number plate recognition system played a vital role in the conviction of Pc Sharon Beshenivsky's killers.
The gang were caught on CCTV making their way to Bradford
A network of cameras linked to a database of registration numbers automatically alerts officers to a vehicle's route across Bradford.
Minutes after the shooting, police were using it to track the getaway car.
After the gang's arrest, detectives spent months scouring CCTV footage for evidence to secure a conviction.
The CCTV system, called Big Fish, comprises a series of cameras at fixed points throughout the city centre and on major routes in the outskirts of Bradford.
'A lot easier'
Pc Beshenivsky was shot dead and her colleague Pc Teresa Milburn was seriously injured after they responded to an armed robbery at the Universal Express travel agency in Morley Street on 18 November 2005.
A West Yorkshire Police spokeswoman said Big Fish played an important role from immediately after the shooting.
"Most forces in the UK use the Automatic Number Plate Recognition (ANPR) system as a patrol car-based method of checking vehicle identities.
"In Bradford we have taken it a step further by linking this technology to the local authority's network of CCTV cameras which are monitored from a central control room.
"When a car is entered on the system it will 'ping' whenever it passes one of our cameras, which makes it a lot easier to track than waiting for a patrol car to spot it."
The night before the robbery the gang gathered at a house in Harehills Lane, Leeds, and drank champagne and vodka before going out to a brothel.
The next day, three vehicles used by the gang - a black Mercedes sports car, a Toyota Rav 4 and a green Toyota Corolla - were captured on CCTV travelling in convoy from Leeds to Bradford.
Moments before the shooting their getaway vehicle - the Rav 4 - was captured travelling along Morley Street.
The getaway vehicle was hired from Heathrow Airport
Afterwards, Muzzaker Shah, Yusuf Jamma and Mustaf Jamma - who is still on the run - were seen running towards the vehicle.
The Toyota was later seen travelling along Manchester Road, out of Bradford city centre and towards the motorway network.
The vehicle was hired at Heathrow Airport on 25 October, travelled to West Yorkshire from London in the early hours of 18 November and returned to London after the shooting.
On 23 November police said they had recovered the car and appealed for anyone who may have seen it on or after the day of the robbery to come forward.
Two days later Yusuf Jamma, who was found guilty of Pc Beshenivsky's murder, was arrested at a house in Birmingham.
Muzzaker Shah, who admitted murder, was arrested in Newport, south-east Wales, on 12 December.
And on 1 February this year Faisal Razzaq and Hassan Razzaq, who were cleared of the officer's murder but found guilty of her manslaughter, were arrested in London.
Now all four men are awaiting sentence for their roles in Pc Beshenivsky's death.