Will a disturbing past affect a relationship?

He has been involved with gangs, drugs, 2 crimes 4 years out of juvenile. He had moved to San Jose from LA when he was 17. He got everything straightend out living with his grandparents getting into a top tier university, maintaining A's, athletics, music and community work. He had recently been involved with a girl for 2 months and everything's going perfectly. But his past haunts him and two sides of him fight choosing wether or not to tell his love of his life about his past. What would a typical woman think of this?