Dale McLaughlin, 16, of Parkside Street, Rosyth and brother Stewart, 19, of Gallowhill Rise, Stranraer admitted their terrifying parts in robbing £800 from the Spar store on Kerrsland Road in the town on 28 August.
Dale was charged with entering the store at 9.30pm with his face masked, brandishing a knife and demanding 18-year old shop assistant Claire Rennie, who was working alone in the store, fill a bag with cash before leaving with the money.
Stewart admitted providing the knife and acting as a ‘look-out’.
The two then made off and split the cash before eventually giving themselves up to police separately just days later.
Robert Fairbairn, defending Dale, told Stranraer Sheriff Curt on Tuesday that the youngster - who was just 15 at the time of the incident and had never been in trouble before - had suffered behavioural issues through his childhood for which he has medicine. But he added that Dale hadn’t taken it that day.
He said that Dale was in the shop for no more than 10 seconds in total during the robbery and that he had assisted police in their investigations.
Police recovered a number of newly-bought sportswear items and £146 in cash from the him.
Murray Robertson, lawyer for Stewart, said the 19-year old student was almost finished his third year at college and had settled down with a girlfriend.
He added that Stewart had been wracked with guilt in the days after the incident and turned himself in to police with the full amount of cash he’d taken.
He said: “He didn’t spend one penny of it. He was never within the premises, but takes full responsibility for his part in carrying out the robbery.
“It really is a balancing act here - on hand we have this lad who is a credit to himself, his father and the people of Stranraer who is involved in the community and had never been in trouble before, yet on the other hand we have the events of August 28th last year.
“There was possibly an element of bravado here - he perhaps hadn’t expected the plan to actually be carried out,” he went on.
Both lawyers said their clients fully understood the fear and terror they caused the young woman and were deeply remorseful.
In sentencing, Sheriff Kenneth Robb said he had the difficult task of balancing out a fair punishment with showing justice being done.
He said: “I’m told Dale was in the shop for a maximum of 10 seconds, which isn’t a long time. Well, it is a long time when you’re 18 years old, working alone in a shop and have a very large blade pointed at you, with someone demanding money.”
He added: “I have to consider both your futures as members of society and how this incident has been addressed by the community. I understand that all the hard work which has been done to help Dale may be undone if you are incarcerated, and all the college studying and positive future may be undone if Stewart is.
“But not to incarcerate you leaves Miss Rennie possibly feeling disregarded and wouldn’t address the horrors inflicted that day. Custody is the only option.”
He said he had reduced the sentence from 16 months to 12 to reflect their handing themselves in.