A knife-wielding would-be robber has been jailed after threatening a shop worker. On October 23 last year, Michael Briggs went into the store in Wrotham High Street and bought some crisps before returning a few minutes later with a knife. The 35-year-old threatened a shop assistant with the weapon and demanded money from the till. The victim refused and when another customer came in he left. Police were called and when they found him they told him to put down the weapon. When Briggs refused and put his hand in a pocket where the knife was suspected to be, further warnings were given before an …