>>They do not care about their safety.<<
That’s why there is a *drop* policy; they also won’t allow you to chase the perp outside the store and try to stop them.
I’m pretty sure you cannot concealed carry, even if you work at night, and can legally do so, as a private citizen.
Safety does not have to be a gun.
Two employees is safety. Safety in numbers.
Either that or do not keep the store open overnight.