A man has been charged with robbery after a 16-year-old was robbed of his phone and gold chain.
Paul Tillett, of Gascoigne Close, South Mimms, was arrested after the incident in Shenley Road, Borehamwood, at 2.30pm last Friday.
Another 16-year-old boy has also been charged with robbery.
Detectives are now hoping more witnesses come forward.
Anyone with information is asked to call the police on 101.