It took the U.S. nearly two years to take into custody the “mastermind” of the Benghazi attack (how one can “mastermind” what was allegedly a spontaneous attack is anybody’s guess). The person in question lived relatively openly in Libya, and even conducted media interviews.
State Department spokes-hack Jen Psaki was grilled about it by Fox News’ James Rosen:
The answer as to why the Obama administration waited so long is that the wheels are coming off everything else and they need to reel in every piece of “good news” they possibly can.
Naturally the Obama administration will try the attacker in U.S. civil court. Nothing like affording constitutional protections to people who have dedicated their lives to loathing the U.S. Constitution.