In the LA Times the shooter Nidal Malik Hasan a religious American muslin has been under investigation by the FBI for anti American comments likening suicide bombers to heroic solders etc. on the Internet.
He became distraught when he got orders to be deployed to Iraq.
On Fox cable news they interviewed a retired Colonel whom had worked with
Hasan stated Mr. Hasan had made remarks in the past that were anti-American among his co-workers.

A brave female civilian Army police officer who was also wounded, shot him multiple times stopping him from committing more carnage.

I feel anger, horrified and sadness. Their are so many unanswered questions, that hopefully will come out in time.