It might be easier for you if you speculate a cause for one person's crime. Do not try to write about ALL crime.
When you write an essay or research paper, it is important to "narrow" the topic a lot so that you can dig very deep and write something meaningful.
If the scope is too broad, it is difficult.
So... how about using the intro to name the crime and criminal and then give a thesis statement that captures, in a single sentence, the main idea of the whole essay.