What ever the persons mental state, it always boils down to ease of access and rapid fire capability. As to statistics since the early 2000's when these shootings amounted to around one a year, it has steadily risen to more than 3 or 4 a year. And it would seem to parallel to the lifting of the assult rifle ban in 2004. Number of people killed in each incident has also increased along these same lines.
Phil
