Schneiderhan was born in Roxbury, Massachusetts to working-class immigrants from Riedlingen, Donau, Germany. He grew up in a tenement at 25 Ambrose Street in Roxbury, Massachusetts, in the predominantly Italian Orchard Park neighborhood where the Patriarca crime family capo Ilario Zannino, Ilario's first cousin Phillip Zannino, and the Flemmi brothers were born and raised. As a childhood friend of the brothers Vincent Flemmi, Michael Flemmi and Stephen Flemmi, he idolized Stephen and maintained a friendship with him into adulthood.