Two robbers lay in wait for a Chartwell Burger King worker to put out the rubbish before pointing a sawn-off shotgun at his head and marching the man back inside.
The thieves had meticulously planned the late-night robbery, waiting for staff to close the fast food restaurant in Hamilton before making the ambush.
Hamilton CIB detective Will Loughrin said the duo, who made off with an undisclosed sum of money following the aggravated robbery last Wednesday, put lives at risk and he is calling on members of the public to help catch the offenders.
"We believe the two men involved had familiarised themselves with the layout of the premises before they struck, laying in wait for a staff member to take out the rubbish after closing, about 11.25pm."
One of the men put the sawn-off shotgun to the head of the worker and forced him back into the store where they confronted three other staff members including the supervisor before stealing the money.