The shooting at the Family Research Council in Washington DC is being investigated an act of domestic terrorism, but how do investigators decide what is terrorism?
FOX News Radio's Jill Nado reports from Washington in our on-going series on national security:
When a military recruiting center was targeted in 2009 by Carlos Bledsoe, who described himself as an al Qaeda operative, the case went to court without terrorism charges.
And when 13 were murdered at Fort Hood by a gunman who allegedly shouted 'Allahu Akbar' or 'God is great', the Defense Department said it was being handled as work place violence. Congressman Peter King, the Republican from New York chairs the Homeland Security Committee.
(King) "Certainly to me, Fort Hood would be the classic case of what should be a clear case of terrorism."
In some cases it may be easier to show the suspect is guilty of murder rather than to prove an ideological motive.
In Washington, Jill Nado, FOX News Radio.