Avon and Somerset police was to identify a masked robber who stole from the Spar in Filton Avenue in Bristol on Sunday evening.
No-one was hurt during the incident - at 9.50pm - but a member of staff was threatened with what appeared to be a firearm.
The man was said to be wearing green trousers and "a muddy black padded jacket". He is described as 5ft 8inches tall, around 30 -years-old, with "very blue eyes".
The offender escaped with a small quantity of money, heading in the direction of Filton.