Hero or Villain?
The nature of man is a complex web of interweaving stories that form the basis of values, morals, and virtues, all of which many would defend to the death. Each person is the hero of their own story, a perspective we all share, told from each of our own eyes. Those around us are our supporting cast of characters, heroes, and our villains. A person's story is so complex that their supporting cast doesn't need to be a person, it can be an ideal, a moralistic goal, or even an object.
We often find ourselves asking of the murderer “how could they do such a thing?”.
We haven't put ourselves in their perspective. Even if we had, in some instances we still wouldn't understand and need to dig deeper. What most of us would find is darkness and, in that darkness, a growing monster. If every person is the hero of their own story, they can also be the monster. The greater the hero, the greater the monster and vice versa. A person who is good but has no backbone is not really good at all, but harmless. These monsters are akin to snakes. A person who is good with harmful capacity is truly good, as they're the ones who not only know what is right but can act to correct a wrong. They have tamed and mastered their monster.
So, how can a murderer become a murderer?
The murderer is the untamed monster. They have been swallowed by that monster, living according to its whim. The monster is always there, but how it grows and manifests is dependent on the rest of the story. If the monster is kicked, repeatedly, it will lash out. The monster will justify its actions and see itself as the hero, or at least anti-hero. While it's possible some monsters are larger and more feral than their counterparts early in development, it would seem most grow from constantly being kicked, as if it's being fed. With no mentor to guide the taming of the monster, we find monsters grow like wild grass and destroy whatever is in their path.
Logically, and with the most difficulty, the next question that must be asked is “if the harmless is without a monster and the murderer is simply the untamed monster, is the hero capable of murder?”.
Yes, they are, but won't.
Murder as defined in the dictionary is “the killing of another person without justification.”
How do we come up with justification?
Is a father able to stop a monster attempting to force themselves upon their daughter, even if that means the monster's death?
The vast majority of justifications tend to be self evident, but clarifying whether or not the action fits the justification is the problem. In the example question, the father is the hero, a man who has mastered his monster to stop another, but to protect his daughter. It would be difficult to argue the contrary.
We, ourselves, are not far off from the untamed monster, but if we understand that the hero is the master of their monster, we can move forward to accomplish greatness.