After
I can't vouch for this.
An Anonymous commenter gives us food for thought:
I am absolutely convinced that the regime makes a conscious effort to hide or distort a shooter's on-line history to conform to narrative as much as possible. This is why DHS immediately takes over the scene and withholds the shooters identity.
I am also certain that there is a designated task force in DHS/NSA dedicated to rapid response to such situations and that Obama's remarks have been written beforehand waiting for an occurrence.
It is not too much of a stretch to imagine that their are DHS operators who actively seek out disturbed individuals identified by NSA data mining and encourage them to act out violent fantasies.
How do we know that the people posting encouragement to the deranged posters are not government agents?
These assholes are trying to start a Civil War. The ultimate crisis (and they won't let it go to waste.)