As if they were so kind as to advertise who they are and not lie about their motivations. For example, the leader of Ansar-al-Sharia in Benghazi was supposedly identified within 24 hours as one of the consulate assault leaders. He's denying it, saying he was there but the crowd was incensed by the video after all. He couldn't control his crazed followers. Riiiiiiiight.
No evidence.
Of course not, instead of sending in the military immediately as is appropriate for an act of war, Obama sent in the FBI (treating it like a criminal investigation).
FBI couldn’t get there for several weeks. Out post was not secured, evidence would have disappeared or been compromised by the time they got there.
Any time you hear or read those weasel words, No Evidence, ignore what follows - it is probably a white wash.