S.E. Cup was on the panel this week on Real Time with Bill Maher and she claimed that mass shootings had decreased so I did some googling and found this article...
Source: Los Angeles Times
"What we’ve seen after Aurora and what we’ve seen after Newtown is kind of the typical response that we’ve seen over the last 50 years following high-profile mass public shootings," said Grant Duwe, a criminologist for the Minnesota Department of Corrections who's written a book on the history of mass murders since 1900.
“We had mass public shootings before 1966, but the frequency with which those cases occurred is less than what we’ve observed since the mid-1960s,"
The country saw an increase in mass public killings during the 1980s and '90s, but Duwe's tallies showed that mass shootings had decreased since then. The 26 public shooting massacres he tallied between 2000 and 2009 were significantly down from the 43 cases he counted in the 1990s. (Duwe counts shootings in public places that result in four or more dead, but he excludes robberies and gang violence.)