We know more about what happened in Benghazi, than what happened in DC regarding the attack. And Obama is simply stalling and covering up the truth by "investigating". But we don't need any investigation, Obama can simply tell us what he knew and when he knew it, as well as Clinton and Panetta. I don't expect to hear a word out of them, because they are simply liars more interested in their personal interests, than the interests of the country (or the lives of Americans, even American ambassadors, much less common citizens).
He should be impeached, and will likely be after the election if he wins.