The son of notorious Mob associate Danny Estacado and an unnamed prostitute, Jackie was taken in by Saint Gerald's Orphanage where he was frequently abused by the orderlies. Despite his antisocial nature even as a boy, Jackie protected his friend Jenny from their cruel treatment. At the age of six, Jackie was adopted by upcoming Mob boss Frankie "Kill-The-Children-Too" Franchetti, claiming to be his uncle. He only did so after being persuaded by Sonatine of the Brotherhood of Darkness that bringing Jackie into his inner circle would make Frankie powerful.