Police in Rushden are appealing for witnesses to a robbery that took place at 6.40pm on Sunday, July 15.
A 13-year-old boy was walking along Irchester Road, Rushden, near to Knuston Hall, when he was approached by a man who demanded his mobile phone.
The teenager handed over the Samsung phone and the offender made off.
The offender was white, 30, and was wearing a black vest top, white jacket, dark coloured jeans and black trainers.
Officers would like to speak to anyone who may have witnessed this incident or who may have any information regarding it.
A 23-year-old man has been arrested in connection with this incident and released on bail pending further enquiries.
Witnesses to this incident, or anyone with information, should call Northamptonshire Police on 101 - alternatively, information can be given anonymously to Crimestoppers on 0800 555 111.