Structural innocence refers to the reason why a victim is chosen in a scapegoating situation. There may be a superficial reason, and there may be a deeper, more substantial reason which is the real hinge of the scapegoating mechanism.
For example, a young Latino student is expelled from school on grounds of sexual harassment. Although the student may be genuinely guilty for their misdemeanor, the expulsion may have little or nothing to do with the act itself, and much more to do with relieving interracial tension in the community.
In that way the student could be understood as being ‘ Structural innocence’, a victim of a much larger, unseen, scapegoating conflict.