They aren't going to have anything as long as this continues in the same manner; a sudden single shot, little or no report, a victim slumps for no apparent reason, people rush to her aid, find her dead and then become concerned for their own safety and seek shelter.
After a bit of time passes uneventfully, those who scattered re-gather and "compare notes", repressed memory takes over and white (now cream-colored, sodium vapor lights?) vans career out of the woodwork and the pot-load is long gone again.