HUH???
Possible Reason #1) Member of a "protected class" -- i.e. non-white.
Possible Reason #2) Middle eastern men on their 20's-30's.
Possible Reason #2 is my bet. The authorities want to catch these perps without making an announcement that some middle eastern men on their 20's-30's are responsible. The public would be outraged, and it could very well lead to "open season" on anyone who fits the profile -- about as close to out of control as the situation could get.
they are ex-cons who took up "the religion of peace" and were released on liberal parole.....