A woman cashier was threatened during an earlier robbery at Iceland in Redruth
Police in west Cornwall are investigating a third armed robbery in the Redruth area in a week.
The latest robbery occurred just after 20:00 GMT on Monday at the Spar shop in Fore Street in Pool.
The offender entered the store and threatened the shop assistant with a Stanley knife before making off with a quantity of cash from the till.
Police said the other incidents happened at the Iceland and Co-op stores in Redruth.
Det Insp Chris Strickland, from Devon and Cornwall Police, said: "We suspect there are links, we can't say for certain.
"We have got certain leads. I am hoping we will be making an arrest fairly soon."
The suspect in the Spar theft is described as white; he wore a blue-coloured hooded top with what is thought to have been a striped T-shirt underneath.
- Published6 February 2012
