Legal Question in Family Law in Illinois

Can you afford the GAL/Child Rep Fees?

Obtaining custody of any child is a very costly undertaking. In addition to your own attorneys fees, you will likely have to pay at least one-half of the fees for an attorney for your son and you are setting yourself up for Mom to ask for an increase in current support since your income will be an issue to be considered.

With that warning in mind, the facts as you present them aren't conclusive for either parent. You are not immediately disqualified from getting custody of your son because of a single felony conviction, particularly one that long ago. OTOH some of the facts that you list regarding step-dad will be hard to prove if Mom & step-Dad deny them. Its very doubtful that the sister could be called to give testimony and its likely no one will even allow her to be interviewed. These cases are very fact specific and your question suggests that you are trying to prove that Mom should not have custody based on the conduct of a third person, the step-Dad who the court doesn't have jurisdiction over.

Your best bet is to try and convince Mom to let the boy come live with you in a test run. There may be other issues that exist which would effect your interest in obtaining custody of your son at this point in his life