The gang of five drove several hours from Greater Manchester to target a family-run shop in Newcastle upon Tyne before subjecting the owner to a terrifying raid.
Armed with sledgehammers, they carried out their 'highly organised' and 'ruthlessly executed' operation in broad daylight, smashing display cabinets before making off with some £300,000 worth of jewellery.
In a terrifying operation, the raiders used sledgehammers to smash into display cabinets and steal expensive goods.
As the shop owner desperately tried to stop the gang, one thief lifted a sledgehammer above his head so the group could make a quick getaway.
Neither the jewellery or money has been recovered.