Overview
Firstly, consider using Compliance Week or Accounting Today to find a case/investigation/etc. (you are not limited to using those two sites).
Then, this time, after providing a background on the case, think about, specifically, how you and your team would proceed with a plan for interviews. Of course, the interviewees could be witnesses, victims, cooperators, co-conspirators, supervisors, co-workers, or even the subject him/herself. Consider things like who you would interview first/last, how you would get in contact with those involved, where you would hold interviews, who you would include in the interview room(s), how you would go about introducing evidence, what kinds of questions you would ask (and not ask), and anything else you may want to include. If you come across specific information regarding interviews that were in fact conducted, even better; feel free to offer your feedback on what occurred and if they seemed to be helpful to the case.