If they wanted to create terror, they are right on track.
Back around the July 4th terror alerts, I sat down and tried to think where and what form the next attacks would take. I figured airplanes were probably knocked down the terrorists' list because of all the security and passenger reactions. Car bombs would be locally effective but wouldn't have the dramatic effect of 9/11, so people, nationwide, would almost be more relieved than terrified. A nuke would be their ideal but I don't believe they have the capability in the US yet.
Where I ended up was with the thought that if a terrorist wanted to really terrorize, he would randomly and anonymously attack individuals in the heartland of America. Then, no where would seem safe. I thought it would have been somewhere in the mid-West but I suppose they could have picked Maryland and Virginia. I would not be the least bit surprised to find out this was the case with these shootings.
Only partly.
If they start making normal people targets, people will begin carrying, laws or no laws.