Criminals, people who commit crimes, usually society rejects these people. They are also part of our society. Give them some form of punishment to say they were wrong, but show them they are part of society and can change. Show them compassion.
Apart from selfish reasons, such as fear of punishments, fear of blame, of dishonour, etc, there remains only two motives that can stop (or prevent, "empâecher", Fr.) men from acting badly; the natural sense of commiseration (or "sympathy", - "commisération", Fr.) for one's fellow men - compassion, and the influence of education, by association of ideas ("par l'association d'idées", Fr.) - habit.
An important distinction can be made between religion and spirituality. Religion [is] concerned with faith in the claims to salvation of one faith tradition... Spirituality is concerned with qualities of the human spirit, love and compassion, patience, tolerance, forgiveness, contentment, a sense of responsibility, a sense of harmony, that bring happiness both to self.
I think there is a complicated side effect to overcoming evil in that we are forever changed by it. I think after we ingest some of the cruelty of the world, it takes years off of our lives, but it also gives us wisdom and a little grace, hopefully a sense of compassion.
We are beset by problems and if we look for their source, we find they arise because of our selfishness, because we tend to pursue our own interests at the expense of others. Our various religious traditions exist to help us reduce these problems. They all teach ways to overcome suffering through cultivating love and compassion, tolerance, patience and contentment.