Capturing the twists and turns of major crime investigations as they happen, the series will follow serious criminal cases and show the vital work of police forensic services in building evidence and solving crimes.
　　Police work that relies on hard factual evidence is more vital than ever and convictions today can rest on tiny margins. The path of a bullet through a pane of glass; the chemical make-up of a petrol bomb at the scene of a fire; the drop of saliva left on a victim's clothes. As criminals have become more sophisticated in recent years, forensic science has made huge advances and the role of Crime Scene Investigators has become more and more vital.
　　Northumbria Police is one of Britain's largest forces, covering an area of over 2,000 square miles and a population of more than 1.5m people. The patch encompasses the urban sprawl of Newcastle as well as tiny former mining villages; from the Scottish border down to County Durham, and from the Pennines across to the North East coast.
　　Different episodes will follow individual crimes from the moment of call-out across this vast area, showing how CSIs gather and assess evidence from DNA to blood spatter, digital forensics to footprints - and how they work closely with CID detectives driving individual investigations.