How to research for a father that used aliases.

Question

I am the youngest of my immediate family. We have extensive genealogy on my mother's side but have mostly unknown on my father's side. My father was found to be somewhat untruthful about his past.  He left my life when I was 5 and became a Christmas/Easter Dad. He died in 1967 and research performed by an older brother found out that he had used several aliases and "conveniently" was born on Ellis Island and when his father and mother died, he was put in orphanage that "conveniently" burned down.  In his research, my brother got a letter from the State Bureau of Investigations that gave him the aliases and said we shouldn't ask for more.

Answer 1

The easiest way I found is to research the mother first. My great grandfather went by a different last name until he turned 18. He was using his step fathers last name so it was hard for me to find anything until I started looking for his mother.

Answer 2

Uncle Joe, Are you referring to Baker? if so, Mother didnt tell us much, she did say that he left and dad took the Obannon name. I have been searching myself for Baker side and cant find anything, if I do will let you know.