Just in case you don't have your answer, the person responsible is the person who took your property, and your witness is the roommate.
and there is a SOL so contact the police see if they will take the criminal complaint this late in the game, and here is the website for suing civilly
http://www.georgiacourts.org/aoc/selfhelp/civil_cases.html
please note you can apply for a low cost lawyer to help you.
good luck.
Ps, just because you get a judgment (not saying you will...) does not mean you will get paid on the judgment