The main difficulty in answering this question is that what you include in your outline depends on the sort of paper you want to write. There are several different standard types of paper one writes in graduate school, and each type has a distinctive style and set of standard rhetorical forms.
One possibility is a literature survey. In such a paper, you survey existing scholarship on a specific topic, usually by breaking it down into subcategories and then within each category moving chronologically. Thus you might begin by surveying philosophical work defining the concept of egoism, and then look at the different ways scholars in the criminal justice field have used the concept.
Another possibility would be an argumentative paper, taking a particular stance concerning ethical egoism as a descriptive or normative ethical system. In light of one of these, you might argue about whether such a position precludes a moral basis for criminal justice and leaves the field as a purely pragmatic response to conflicting egoistical desires.
A third possibility might be to study how egoism might serve as an enabling ideology for criminals. In such a case, you might wish to do a metastudy based on existing primary research.
Finally, this assignment might be geared more towards an undergraduate style of writing in which you simply provide a basic summary of the topic, first defining what the term means, and then discussing which particular aspects of the philosophical position have applications to criminal justice.
As you refine the focus of your paper, it will be easier to develop an outline, but your first step should be analyzing the assignment itself in detail to get a clearer sense of the main focus of the paper.