Charleston is considered a very safe, midsize city. You can feel quite secure in the downtown Historic District (from Broad Street, to Upper King Street, Mary Street, and slightly beyond) even until midnight during the week and later on weekends. In neighborhoods where there is public housing (especially off upper King Street in the direction of Spring Street), you would not want to walk around carefree, either by day or night. A lot of late-night street crime is directed at those who drink too much, making themselves easy marks for robbery. Do lock your car doors, and do not leave valuables in sight. Full shopping bags, luggage, and laptops will be particularly tempting in hard economic times.
Distribute your cash, credit cards, IDs, and other valuables between a deep front pocket, an inside jacket or vest pocket, and a hidden money pouch. Don't reach for the money pouch once you're in public.