Sustained Sequences of Non-Spectacular Terrorist Attacks

In most years when I teach my seminar on the history of terrorism and US counterterrorism law  and policy, the question arises why terrorists do not more frequently embrace the "Beltway Sniper" model--i.e., one or a few persons engaging in relatively random, one-off shootings, with a high-probability of tactical success and of remaining free to act repeatedly, as opposed to reaching for difficult-to-achieve, high-intensity attacks  like bombings of major public buildings.  Someone usually points out that the latter, if successful, will generate a huge amount of attention, while any single killing along the lines of a shooting will resonate far less.  Someone else then usually points out that a sufficiently sustained sequence of low-intensity attacks could in fact generate quite a panic, ala the Beltway sniper.  I usually end the discussion by thanking God we don't actually see that latter model put to the test.  When I heard a few mornings ago that there had been a second drive by shooting of French soldiers, in France, I became quite concerned that this was precisely the scenario unfolding there.  Now comes word that the same shooter (or at least the same gun) has killed a teacher and three children at a Jewish school in Toulouse.  It may be, in the end, that these murders are just that, murders without political motivation.  It may be, though, that we are seeing an example of the comparatively easy-to-achieve model of low-intensity terrorism.