Scholars today hold that before the gospels were written, the story of the Passion of Jesus had already been told and retold and put into writing. In fact, the first gospel of Mark is something of a Passion Narrative with an extended introduction. The original account of the Passion began with the arrest of Jesus in the Garden of Gethsemane.
The Church clearly teaches Jesus’ betrayal is the sin of each one of us. It is not the crime or treachery of one individual, or one group of people, let alone an entire race. Christ died for all sin. And every sin finds its ugly traits on the face of Judas.