There are literally hundreds of links covering FP and Fort Hood. Having just recently performed FP for visiting Sailors and having tons of time on my hands to read through reams of regulations, I recommend some light reading on the current thread.

A very general overview placing blame and responsibility on the installation commander:

Military Operations
UNITED STATES ARMY TRAINING AND DOCTRINE COMMAND (TRADOC)
FORCE PROTECTION PROGRAM (FPP)

Stand-To
Fort Hood Army Internal Review Team
Scroll down to resources for the links

Interim Fort Hood Recommendations Approved

Then Army dot MIL
Protecting the Force: Lessons learned from Fort Hood

And DOD's independent review, which has some equally depressing and promising recommendations:

There's a every so slight recommendation revolving around Active Shooter Tactics and the lack thereof on bases. Sadly, the review concentrates more on identifying the threat and lack of communications as the problem.