You have left out, from your conclusions, that Hasan - the murderer from Ft. Hood - was previously diagnosed with a mental disorder.  That is the issue behind most of these mass-murder occurrences, and, sadly, most often brought to light way after the shootings.  It has nothing to do with "the present administration" or the lack of vetting immigrants.  That is a purposely made-up lie for the purpose of inflaming specific parts of the citizenry who are steeped in racist thinking and ideology.  It seems, utiltas, that you yourself follow a very racist set of beliefs, and twist facts to bolster those attitudes, but the hundreds of investigations into the matter speak with one voice: you are wrong.  And BTW - we have two immigrant families living with our community (one is from Syria).  You may want to get to know some yourself, so you can learn just how wrong your ideology is.  Try it.