Trust me, craigslist is a shady place to be getting a snake from! Like dalvers63 said, check with your local herp. society first if you're looking to adopt.. I've bought/traded snakes from 4 people that are part of the AZ herp. society and have never had a problem once!

If you are not looking to adopt then check out some reliable RTB breeders that could ship you one, you can check breeder reviews too.. that way you know what other peoples experience has been with them before you purchase from them.