Given the high cyclic rate of fire sequences - - interspersed with pauses to change magazines - - heard on in situ sound recordings of the event, it seems likely the shooter did indeed use one or more fully automatic weapons. If memory serves, since 1934 these have been outlawed for private ownership unless one is a federally licensed fire arms dealer.

For that reason, one supposes the shooter had to make extensive preparations for deliberately orchestrating this life ending event. 

This gives rise to a question: Has there been any sort of study to determine if during such extensive preparations, a prospective shooter typically emits any kind of behavioral pattern or signature that law enforcement specialists might be able to use “big data” technology and techniques to detect and analyze? 

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