Anytime someone files a Petition for a TPO, if the allegations are not baseless on its face, the police are required to act on it. The "rule" is to grant the protection until a hearing is conducted, then determine if an actual order of protection should be awarded. Thus, your arrest was proper. However, if your ex has not legitimated the child, he had no legal right (no custodial rights) to him. It is strange that your ex was allowed to take your child (without first requiring him to produce a custody order).
I must disagree with my colleague. Yours is not a family law issue (at least not yet), but rather possibly one of abuse of process, intentional affliction of emotional distress, and/or some other tort. You need a general civil litigation attorney. (But one who is at least familiar with family law, and specifically with issues concerning child welfare.)
Since ALL Georgia attorneys must be members of the State Bar in order to practice, the membership is irrelevant. Actually, so is being "active" in other associations and organizations. What matters is 1) that they know what they're doing / talking about; 2) that they understand what your concern is and what you're wanting as an outcome; and 3) that you're comfortable working with them.
You need to contact a number of attorneys, interview them (and discuss the details of what occurred and what resolution you're seeking), and then settle on one.
Good luck dealing with this situation (and those potentially to come) with your ex.
~ Kem Eyo
The above answer is a general explanation of legal rights and procedures. It does not constitute legal advice. Nor does it establish an attorney-client relationship between the individual posting the question and the attorney providing the answer.
YOu need a strong well versed Family Court trial lawyer. This person must be smart and hard working. He should be active in your local bar association but also maintain membership in your State bar. If he has written legal articles about custody and abuse that is a plus. Further you should check him out here on AVVO and see what his colleagues think about his work. He doesn't have to have a 10.0 ranking but a strong 7.5 or better ought to be good. Don't base your lawyer decisions on price alone, though it is often a strong consideration, this is your child and home life you are talking about and you want the best lawyer you can afford, If the guy you want is less expensive great but truly in law you get what you pay for usually so be prepared for stiff fee, especially since it sounds like your ex likes a fight and has very dirty tactics.
This answer does not, nor is it intended to, create an attorney-client relationship or constitute attorney advertising. Rather, it is offered solely for information purposes. Since the facts of each case are different, it is critical to consult with qualified counsel with whom information can be shared and assessed under an attorney-client privilege, so that competent advice can be obtained on which you can make informed decisions.