A masked man threatened a Lincoln shop assistant with a knife on Monks Road in Lincoln.
The attempted theft happened at around 7.40pm on Friday, October 25 at the Mini Market. The man demanded that the shop assistant handed over money.
He was not given any cash and, after what police describe as a brief altercation, he ran out of the shop onto Monks Road.
Nobody was injured in the accident.
A Lincolnshire Police spokesperson said: “We would like to trace the individual shown in the photograph in relation to the investigation. The clothing he is wearing is distinctive and is believed to be by Under Armour.”
Anyone who knows who he is or recognises the clothing is being asked to call Lincolnshire Police on 101, quoting incident number 371 of October 25.