An E-Fit image has been released by Thames Valley Police of a man in connection with a robbery in Chalfont St Giles.
At around 4.30pm on Friday, September 6, the victim, a teenage boy, was walking along High Street when he was approached by another man.
The offender demanded that the victim hand over a ring he was wearing and threatened him by showing the handle of a gun that was tucked into his trousers.
The man took the ring and ran away in the direction of The Green.
The victim was not injured.
The offender was white, approximately 5ft 10ins tall, of lean build and aged in his mid to late teens. He was wearing a grey and black North Face jacket and spoke with a local accent.
Case Investigator Hazel Browne, based at Amersham police station, said: “I would like to speak to the person depicted in this E-Fit image, or anyone who recognises him.
“Anyone with information can contact police by calling the non-emergency number 101, or make a report online quoting reference 4319 0276 193.
“Alternatively, if you wish to remain anonymous, you can contact the independent charity Crimestoppers on 0800 555 111.”