A teenager has been charged for her part in the armed robbery of the St Helens BP service station on September 23.
Police charged the 18-year-old Newstead woman today.
The woman was also charged with two counts of motor vehicle theft.
Police say that on two occasions on the weekend before the robbery, she stole cars in Launceston and used them to drive to St Helens, later dumping them in Newstead and Waverley.
She will appear in the Launceston Magistrates Court next month.
The robbery occurred about 2am when the woman approached the glass front door of the 24-hour service station in Circassian Street.
When the attendant opened the door remotely, a man ran into the store, where he threatened the attendant with a gun and demanded money.