I'm not crazy familiar with the law, but in a case that happened to a couple I know personally they kept a relationship with the bio-mom. Well one day on a visit she abducted the child. It took awhile for them to get her back and it almost looked like they wouldn't. Basically what saved them was that she adducted the child. If she had properly gone through the court system likely they would have given the child back to bio-mom.