Here in L.A. a few days ago, on Talk Radio, a couple of guys called up, one was L.A.P.D. retired and the other was a 20 year Special Forces vet. They both said that the .223 caliber used is considered an 'international' round, one that can be used in the Kalishnokov (AK-47)... it's not rare to find here, but not common for use either. It was their opinion that it could be terrorist related since it is in the D.C. area, the guy appears to use intelligence in selecting targets, and the round is the type that 'terrorizes' in that it tears up a person internally. (sorry to be so discriptive) ...