I did some research and came up with some possibilities.

I haven't read them yet so it's a shot in the dark.

Exploring Terrorist Targeting Preferences
http://www.rand.org/pubs/monographs/MG483/

Combating Terrorism
How Prepared Are State and Local Response Organizations?
http://www.rand.org/pubs/monographs/MG309/

Of course RAND has an entire section called..... "Terrorism and Homeland Security"
http://www.rand.org/pubs/online/terrorism/