We need to FACE the fact that it might be a domestic extremist group.
You are correct. It could be domestic. Nobody knows yet.
part of the reality of living in the USA is that these things can happen.
Only if it's domestic. If it's a foreign terrorist the US State Department would be responsible as they are the ones handing out VISAs or Homeland Security's responsibility if the attack was done by an undocumented foreigner here illegally. Under these two circumstances such an attack can only happen if our federal government fails us.
Let’s face it... Al Qaeda has been coming over the southern border for years.
The have found indicative items there.