In case anyone is interested, here are
A list of well known mass shootings.
http://timelines.latimes.com/deadliest-shooting-rampages/
It looks like they are becoming more frequent. From one every few years to one every few months.
A site tracking all mass shootings in 2015 year to date. This site includes shootings where "only" a few people are killed or wounded.
Mass Shootings in 2015 - Mass Shooting Tracker
Maybe mass shootings will continue getting even more frequent. Every few months - how about every couple months - then every month - then . . .
If that happens, there WILL be gun control. Will it be sensible, like the measures I listed, or not?