A thief grabbed £300 from the hands of a customer in a jewellery shop.
The man walked into Nelken Jewellers, Shenley Road at around 1pm on Friday, March 31 before taking the money and running out of the store towards Theobalds Street.
Police have released a CCTV image of a man they would like to speak to in connection with the theft.
Contact Detective Constable Stuart Keene on Hertfordshire Constabulary by calling 101 or contact Crimestoppers on 0800 555 111 or visiting. www.crimestoppers-uk.org.