This mall is a property of The Mills Corporation and like all of the other malls that they own their code of conduct states:
CONCORD MILLS CODE OF CONDUCT
Concord Mills, including its designated roadways and parking lot, is private property. The following Code of Conduct is set forth for the purposes of protecting Concord Mills’ legitimate business interests and any violation to the Code interferes with the commercial nature and function of Concord Mills. Your entry constitutes your consent to abide by all the posted rules governing conduct, traffic, and parking.
AS A VISITOR AT CONCORD MILLS, YOU ARE PROHIBITED FROM ENGAGING IN ANY OF THE FOLLOWING ACTIVITIES WHILE AT CONCORD MILLS:...
...17. Possession or carrying of any firearms, simulated firearms, or weapons of any kind, openly or concealed with or without permit, is prohibited.
Notice that there is no exception made for LEOs either.