On another thread, I speculated that the shooter(s) may want to get out of town like they did last Friday (2:30pm shooting in VA). I guessed they could go West on 66. I am not a big believer in the Michaels theory but there are three Michaels stores right off 66 going West. They are in Fairfax, Centreville and Manassas. I checked MapQuest and all of them have a park within 900 feet.
Not good. Should perhaps have LE in each park, just in case. (course, we don't know, they might be doing that, by now)