My question involves a child custody case from the State of: Missouri

I am only beginning to research this topic, so really I just need to know where to start. I left the Caribbean when my son was 2 months old due to a very violent and drug/alcohol filled situation. His father had warrants out for his arrest and has since gotten them cleared from his name. He has also gotten himself clean and sober over the last couple of years. He is now currently on parole, but his criminal record is lengthy and involves very violent acts involving firearms, robbery, auto theft, etc. He has suddenly shown avid interest in pursuing legal visitation of his son. I have a spotlessly clean background and record and have never been convicted of anything, much less convicted of felonious crimes. My son has a very steady, Hallmark Channel type of upbringing, here Missouri. Beautiful spacious home, health insurance, loving family all around, wonderful child care, in a very safe part of town. Should I get a court-appointed attorney and take this to court, what are some speculations on his ability to gain legal visitation? Would they be supervised? What would the courts take into consideration? It's obvious that my son's best interest is most definitely here with me...but what exactly could he fight for and how far could it go? My son is 3 years old, so I doubt flying him down for summers would be a possibility this young, and with the father being absent for these entire three years - practically a stranger.

Thanks.