Great article on FiveThirtyEight on gun violence, mass shootings and what might work.  Here's an excerpt:

"If we focus on mass shootings as a means of understanding how to reduce the number of people killed by guns in this country, we’re likely to implement laws that don’t do what we want them to do — and miss opportunities to make changes that really work. Gun violence isn’t one problem, it’s many. And it probably won’t have a single solution, either."