A man was robbed at knifepoint in a Northampton town centre alleyway in the early hours of Friday morning (July 11).
A man threatened the victim with a knife and stole his mobile phone in the alleyway between McDonalds and Timpson in Drapery between 4.15am and 4.45am.
The offender is described as a black man, about 6ft 3in, of stocky build, clean shaven, aged about 19 and with a local accent, police said.
He was wearing a black tracksuit and carrying a black man-bag/pouch with the strap across his body and the pouch close to his chest.
Anyone with information is asked to contact Northamptonshire Police on 101 or information can also be reported anonymously to Crimestoppers on 0800 555111.