He took last weekend, "off," and thus far, seems to have done so this weekend. May have a part-time work schedule, or may even just drive a spouse/ domestic partner to work and pick him/her up at the end of their shift. The killer really cut loose on the day his competition for headlines was hurricane Lillie...
FWIW, my bet is that it follows Al Qaeda's pattern of groups.
Two to more cells of two to four.
They want it to appear like the "ghost" in Patriot.
We cannot r/o that a woman is one of the perps, and the COUPLE meets with other couples over the weekend.
The recent distribution of hits below DC might suggest
an origin north of that.
The shooter might take the weekends off to scout out new territory.