If you concerned about crime, your best source of information is the local police department--consider a visit/call and ask all your questions and hear all there is firsthand, they'll gladly help. As for the distance--consider a Mapquest, Google Maps, etc., and check mileage.
You may also want to check out city data (web ref below), Rayleshia. Lithonia is about 16 miles from downtown Atlanta, but the time factor depends on when you make the drive. Figure about 30 to 40 minutes for most workday commutes. Please let me know if we can help further.
check out the website http://www.crimereports.com it has all the data. Plus you can contact your local police department and they will let you know. Most agents don't talk bout crime in the area, but refer you to those who deal with crime, and thats the police.