Go to the York County Gov website and click on "Online Taxes" ... type in just the last name of the person you are looking for ... if whoever has a vehicle or owns property in Rock Hill they will be on the York County Tax Rolls.
If the person owns a home you can take the Map Number from the tax notice ... return to York County Gov homepage and click on GIS Online Mapping and Property Search ... the GIS allows you to search by Map Number for real property.
York County Gov