Take a look at this video:
Beyond the cashier being unfazed by the gunmen, I was impressed by the positioning of the camera which provides a clear shot of the 'customer', the employee and the register with a relatively low and close camera install.
By contrast, more typically I see retailers use wide shots that are positioned way high producing bad angles, poor details, e.g:
What do you think? How have you seen retail cameras typically be positioned? What do you think is best?