Legal Question in Wills and Trusts in New York

As you know there’s a difference between someone who has been missing for 28 years and someone who walked away from their family. In any event it’s a very difficult task to get someone’s birth certificate. I would start with calling the office where those records are kept the county where dad was born is really where you need to start calling and maybe visit and explain the situation and see what they have to say. Have you tried searching through ancestry.com and other public resources to try and track down your dad such as census records and voter registration records another publicly available information ?