Serial Kilker Dissertation Ideas, HELP!Watch
One of the modules in which I do is psychology of crime seen as I do Criminology with Criminal Justice.
One girl in my class did the Serial killers one, and I just remembered I lent a book to another student about Mary Bell who was a child killer. There is also the two boys who killed James Bulger. You could look at child killers and link to the Nature/Nurture debate.
Does your university put up an archive of past dissertations for students to have a look at? That can be helpful with layout and ideas.