Josef Mengele Essay help?

Hi, I'm doing a research paper on Josef Mengele for english, but I'm having trouble picking out a topic/ question. It has to be a good question (How and why's) and it cant be too broad or too specific. Please elp! I need as many topic questions as possible so I can choose. There isn't a whole lot of information on him. I have a book with one chapter about his experiments, so if I could utilize that book, that's be great! I could even maybe do something on survivors of his experiments