I can tell you the only time...and it has happened. I've ceased an investigation, because the law permits me to do so. It's when it becomes extremely clear that we began possibly under a false assumption. For example, we'll start an investigation because we believed someone arranged a meeting. We start it, and then clearly find that no arranging of a meeting occurred. I will cease it. There is no point in pursuing something and possibly reporting to Parliament on something that really wasn't happening.
It doesn't happen very often, but it does happen. With the staff and resources that I have, when it's not worth it because clearly there is nothing there—when the foundation from which we started is not longer there—I will cease it.