A man who robbed a shop with a plastic carrier bag covering his head is being sought by police in Hertfordshire.
The robbery happened on Friday at Day One in Bennetts Gate, Hemel Hempstead, at 08:40 BST.
The man, with a Londis carrier bag covering his head, threatened a member of staff with a knife before taking money from the till.
Police described the robbery as "unusual" and have appealed for witnesses. No-one was hurt.
Officers said the man fled towards Leys Road after stealing the money.
Det Con Paula Mowbray said: "It is quite unusual for a robbery to be committed where the suspect uses a carrier bag as a means to attempt to conceal their identity.
"We would like to speak with the man pictured as he may be able to assist our inquiries. I would also like to hear from anyone who may recognise him."