Where's The Conscience?

Where’s ones conscience in committing genocide. In class we talked about the evolution of the Super-ego , or more simply your conscience. How does this innate reaction not stop people from slaughtering other people?
Freud argues that people develop and Id, Ego, and Superego. The Id is the impulse of want; the superego is societies expectations and your conscience, while the ego is rational behavior.
In an article published by the Ohio State Journal, Joanna Montgomery Byles states: “Freud wrote of the conflict 'between the soldier's old peaceful ego and his new warlike one' becoming acute as soon as the peace-ego realizes what danger it runs in losing its own life to the rashness of its newly formed parasitic double'. Accepting the violence that is within ourselves as well as in the other, the so-called enemy is a difficult lesson to learn, and learning to displace our instinctual destructive aggression peacefully is enormously more difficult. To the extent the individual superego is connected to society, which assumes its functions particularly in wartime, the problem of war brings into focus the psychoanalytic problem of the partial diffusion (separation) of Eros and psychic aggression brought about by war through specifically social processes.” She is simply commenting on how ones superego will change in times of war or in other situational hardships.
But what about those who are heading the genocide? Their superegos are so severely warped that they don’t even no the difference between right and wrong. Society needs to stand up against these killers and make it known that mass murders are not right and will not be accepted.