Trace the responsibility for the shooting to the White House. The FBI is responsible to the DOJ, which is directed by the President (Obama and his brain Valerie Jarrett) The White house instructs the DOJ to back off Muslims, and they pass it on down to the FBI.
So Obama just got 49 people killed and 53 wounded because the FBI could not report what they knew about Marteens connections to Islam. If they had put it on his background check he would not have been able to buy the guns.