Officers in Skegness are appealing for information into an attempted theft and possession of knife in December.
On December 17, a white man, described as being 6ft medium build, wearing a grey cardigan with black markings, jeans, t-shirt, and has tattoos on top of both hands, entered the Oscars store on Lumley Road.
The man took a coat and exited the store without paying.
He was detained by the shop assistant, but the man got away after producing a flick knife.
A spokesperson for Lincolnshire Police said: “We need to speak to the man pictured as he may be able to help with our enquiries.
“Please call 101 and quote incident 257 of December 17 if you have any information.”