Who would be knowledgeable on serial killers?

I have a senior research paper that will make or break my English grade next year. We can do a paper on almost anything but you need a "mentor." I'm considering my topic to be on the mentality of serial killers but I'm not sure who I sould ask to be my mentor. I sent an e-mail to 2 psychologists but I'm not sure they would be able to help me.