If two clerks on duty overnight would bust the budget, perhaps the stores should simply close during those high-risk hours.
Clerks should be trained in how to respond to robberies, what details about the thief to remember and what to do to notify police. Video cameras and alarm systems are helpful, as well.
Owners of stores that are open overnight should talk to authorities about other means to thwart robberies. Police should be able to offer the best plans for self-preservation in such cases.
The problem is not yet an epidemic. Let’s not let it become one.