This week, we've seen a nation can be terrified without the cause necessarily labeled terrorism.
At this point investigators are still looking a motive for, but we have seen other domestic mass casualty attacks where it is clear that the intent is to intimidate and coerce leading some to call for a federal crime of domestic terrorism
"So, I think it's time for a variety of reasons to have a domestic terrorism criminal statute," said former federal prosecutor Mary McCord, who is now at Georgetown Law.
Currently there is a criminal statute for international terrorism, but not domestic, which McCord thinks needs to be changed in the era of mass casualties.
"Violent extremism isn't limited to Islamist extremism or extremism that's done on behalf of at the direction of a foreign terror organization," McCord said.
With no specific penalties on the books for domestic terrorism, mass killers like Timothy McVeigh face charges of using a weapon of mass destruction, or Dylann Roof, who faced murder and weapons charges.
But the label domestic terrorism makes the motive clear, McCord said, in a way that sharpens our response.
"It shows the significance of this type of a crime and why it's important for it to be looked at and treated for what it is, which is terrorism. It's an intent -- it's a crime done for the very purpose of terrorism," McCord said.
Federal domestic terror law would also mean FBI-led investigations -- and the creation of deeper, wider data bases to keep track of mass violence.
Of course here's the potential problem: Labeling domestic hate groups as terrorists -- like al Qaeda or ISIS -- raises constitutional questions.
"That starts to get very close to the line of potentially infringing on free speech, freedom to associate and express one's views, however abhorrent they may be to others in the population," McCord said.
During the Obama administration, the Justice Department considered creating a domestic terrorism statute. As for now CBS News asked the Justice Department if they were continuing the work, and a spokesman decline to comment.