In most states, if you were not married to your child’s father when he was born and haven’t married him since that time, you have sole physical and legal custody of your son. This is a “presumption,” meaning the law assumes it to be true. You don’t have to do anything to establish custody. A presumption puts the burden on your child’s father to file a petition with the court to establish his own custody rights. In most states, he has no rights unless or until he does this.
Custody and Marriage
If you and your son’s father were married, but neither of you has filed for divorce yet, both of you have physical and legal custody. This only changes if one of you files a petition with the court asking a judge to grant custody to one or the other. Until that happens, the law treats custody of your child the same as if you were still happily married. You both have an equal right to spend time with your son. In most states, this is true even if you didn’t marry until after he was born.
Even though you may technically have legal custody, without a court order, the father's refusal to return your son is not a criminal matter, but rather a family court or domestic relations one. Thus, police really can't do anything for you. You must petition the court, asking it to officially award you custody. Filing an ordinary motion for custody can take weeks. Fortunately, in most states, filing a motion to show cause will hasten things along considerably in an emergency. A judge will usually order your child’s father to appear in court within a few days to explain why he should not have to return your son to you. If you were never married, the judge will probably order your son returned to you immediately until the court holds a hearing to decide the father's custody rights. If you were married, a judge might not return your son to you immediately because both you and his father have equal rights to custody. However, he will still schedule a hearing to decide custody.
The courts in most states take a very dim view of a parent who tries to interfere with his child’s relationship with the other parent. After you file an order to show cause, or a complaint for custody or divorce, make sure the judge is aware of what your son’s father has done because his behavior may work against him in a custody decision. You might have a different judge than the one in charge of your show cause hearing, so it's up to you to give him the history of your case. If you were never married and your child’s father can’t prove you’re an unfit parent, most courts will not award him custody instead of you.