Self-regulation is the ability to control your own behaviour and some research links low self-regulation with aggression as well as self-regulation is a limited resource.
When you try to understand or explain a crime, you need to consider both situational factors; like a poor neighbour, abusive parents and having children; and individual factors.
For example, we cannot study rape in a natural setting as this would be extremely unethical as we would effectively be watching a rapist rape a person and allowing it to happen for the sole purpose of gathering data.