Z-Cars
Z-Cars or Z Cars is a British television drama series centred on the work of mobile uniformed police in the fictional town of Newtown, based on Kirkby, Merseyside. Produced by the BBC, it debuted in January 1962 and ran until September 1978.

A rock is thrown at a passenger train and the driver is injured. The Transport Union want the police to take some sort of action, but where do the police start looking for teenage vandals?