Two men smashed through protective Perspex at a Corby store and stole money from one till before taking a second till with them.
Detectives are appealing for witnesses to the armed robbery at Booze Buster in Farmstead Road in the town on Thursday, February 19.
The first offender was a white man, about 5ft 6in, of medium build and had just his nose and top lip visible under a hood.
He wore light grey tracksuit bottoms, dark blue or black hooded top, blue gloves and dark grey trainers.
He had a deep, angry sounding voice, with no discernable accent.
The second offender was about 5ft 4in, and wore black trousers/jogging bottoms, dark coloured shoes, a black hooded top and black gloves.
He was also carrying a claw hammer.
Police want to speak to anyone who witnessed the raid, which took place between 9.15pm and 9.30pm.
They want to speak to anyone who saw the offenders leaving the scene or disposing of the till which was a metal drawer case measuring approximately 50x50x15cm.
Witnesses or anyone with information about the armed robbery is asked to contact Northamptonshire Police on 101 or call independent charity Crimestoppers anonymously on 0800 555111 or use the anonymous online form at www.crimestoppers-uk.org.