Answer:
Yes, no human is born innately evil or good; eveyone is capable of any action. If a person has the mental capacity then they could truly become evil. Whether or not a person is capable of evil is based on the situation and events they have experienced. Since anyone would go through anything at any point, anyone could, theoretically, be truly evil. Everyone has their limit for what they can handle. Once this limit is exceeded, there is no way to ensure that someone will not become evil. There is no way to 100% guarantee how someone will act or how they will turn out.