As of today, there have been 70 mass shootings in the United States between 1982 and 2012, leaving 543 people dead (assuming the reports of 27 fatalities from today's shootings are correct.) Seven of those 70 shootings occurred this year. Sixty-eight of those 543 victims were killed this year. If the scenes of horror and heartbreak are now familiar, it's because the past six years have been particularly bloody. Fully 45% of the victims of mass shootings in America over the past three decades were killed since 2007. That is a crisis.