While crime rates are indeed above national averages in much of South Carolina, especially in inner city areas, incidents of crime in the more heavily trafficked tourist areas are no more common than anywhere else. In fact, these areas might be safer because of the amount of foot traffic and police attention.
By far the most common crime against visitors here is simple theft, primarily from cars. (Pickpocketing, thankfully, is quite rare in the United States). Always lock your car doors. Conversely, only leave them unlocked if you’re absolutely comfortable living without whatever’s inside at the time. As a general rule, I try to lock valuables—such as CDs, a recent purchase, or my wife’s purse—in the trunk. (Just make sure the “valet” button, allowing the trunk to be opened from the driver’s area, is disabled.)
Should someone corner you and demand your wallet or purse, just give it to them. Unfortunately, the old advice to scream as loud as you can is no longer the deterrent it once was, and in fact may hasten aggressive action by the robber.
A very important general rule to remember is not to pull over for cars you do not recognize as law enforcement, no matter how urgently you might be asked to do so. This is not a common occurrence, but a possibility you should be aware of. A real police officer will know the correct steps to take to identify him or herself. If you find yourself having to guess, then do the safe thing and refuse to stop.
If you are the victim of a crime, always call the police. Law enforcement wants more information, not less, and the worst thing that can happen is you’ll have an incident report in case you need to make an insurance claim for lost or stolen property.
Remember that in the United States as elsewhere, no good can come from a heated argument with a police officer. The place to prove a police officer wrong is in a court of law, perhaps with an attorney by your side, not at the scene.
For emergencies, always call 911.