I don’t live there and really know nothing about it so I hope this is not lame but this is what is online:
https://viatravelers.com/is-charleston-safe/
The tourist part is very safe and I used to visit the place a lot.
Much of the surrounding area is very low income. I never had the slightest trouble.
My mother looked at living on one of the barrier islands but a “monkey house” on stilts was not her style.
I stopped reading right there.