I was away on vacation during most of the sniper incidents so I'm not certain of the time lines, but I have heard that so far there have been 9 killings in 11 days.
If this is the case and if the killings cease then the symbolism would strongly suggest an Islamist terrorist or a sympathizer.
I don't know about the timeline, I would have to look it up but there have been 9 deaths in 11 attempts.