Police have one man in custody but are searching for a second.
Stevenage jeweller John Lyons was targeted by thieves yesterday afternoon when two men entered the shop in the West Gate shopping Centre and stole jewellery from a locked glass cabinet.
One man has been arrested and charged with theft in connection with the incident, but police are appealing for witnesses to trace the second man.
Hertforshire Constabulary said that some of the stolen items have been recovered.
John Lyons is a family-run business that runs a watch and jewellery repair service as well as selling gold and silver jewellery.