While the rest of the UK has struggled to contain rising levels of knife and gun crime, Scotland has dramatically reduced violent crime in the past 15 years. But how was it done? Kate Silverton films with Police Scotland’s Violence Reduction Unit, which tries to prevent crime by offering more help and compassion to those at risk of offending. They call it a public health approach, which treats crime as a disease. Panorama weighs up the evidence to see whether it really works – and if it can be transferred to the rest of the UK.