The teen was arrested and charged on Wednesday. He faces two charges, one of attempted robbery and one of possession of an offensive weapon, the Opinel knife used against the shop worker.
The incident prompted an investigation by the Serious Crime Unit after a shop assistant was allegedly threatened with a knife. No one was hurt in the incident.
While the investigation is continuing, the police still want to speak to anyone who may have seen anything suspicious in the area on Friday evening.
A spokesperson added: “We would like to remind the community that these types of incidents are thankfully rare in Jersey and we continue to work with our partner agencies to reduce the risk to the community of these types of crime occurring.”