Criminology dissertation ideasWatch
What I would say is, start off by thinking of a vague topic that you enjoyed covering in your classes or that you know you're interested in anyway. It has to be something that you want to research for or you'll lose motivation so fast. Then start to read around it, and begin narrowing down your topic. For example, being interested in youth offending to I am interested on the effect green space can have on youth offending.
You will hopefully find a gap in the literature, that's where you should resesarch. For example, if there is a lot about male youth offending, but not much about females, you could say- the literature does not talk much about female offenders, so I will invetigate the effect green space has on them.
This is very hypothetical, but what I was advised to do. Most importantly it needs to be a subject that you care about, and that is different for everyone. Hope this helps!
As someone has already suggested, think about areas that interest you and do some wider reading, looking for gaps in the literature that you can develop into a research study.
Also think about what is expected. For instance, are you required to undertake primary research, or can you rely on secondary sources?
I think serial killers will be a difficult subject to cover, depending on what you wanted to do. There are options for the police though. You could look at something around:
Perceptions of Appropriate Adults?
Institutional Racism? - The Macphearson Report highlighted the need for greater representation of BAME officers in order to strengthen community relations. However, there is still disproportionate numbers of serving BAME officers.
Application of Police Discretion?
I'm not saying that one of these topics is something you have to cover, more just to offer some areas for further investigation to see what already exists, etc.