Anthony Mirra being betrayed by his uncle, Alfred Embarratto, and especially his cousin Joey D'Amico. Mirra was already cautious and marked for death but trusted D'Amico. He gave D'Amico a ride sometime in the early 80's, and he was shot dead. - Betrayed.

Can't forget; Angelo Bruno being betrayed by Antonio Caponigro. One of his top advisors.

Phil Testa; Betrayed, and blown to death by some of his men.