Fatal mass shootings becoming more common

US Rep. John Lewis (left) wiped his eye as members of Congress congregated for a prayer circle honoring S.C. shooting victims outside US Capitol.Yuri Gripas/REUTERS

Columbine. Sandy Hook. Fort Hood. Charleston. And now a nightclub in Orlando, Florida. Bloody days like these can seem frighteningly random, but there is a pattern. Over time such tragedies have grown more frequent.

Throughout the ‘80s, ‘90s, and aughts, fatal shootings like this took place roughly once every six months, but in recent years the pace has more than doubled, according to data collected by Mother Jones covering incidents in which a shooter murdered four or more people.

FBI studies have yielded similar findings.

In 2014, the agency undertook an analysis of “active shooter” incidents, which are defined slightly differently but which tend to capture the same kinds of events: public killings or attempted killings whose reach extends beyond a suicide or domestic dispute and implicate a whole community.

From 2000 to 2006, there were 6.4 active shooter incidents per year. From 2007 to 2013, there were 16.4.

As to why such public killings have become more common, there’s simply no consensus. It could be a statistical fluke, the product of loose gun laws, a failure of our mental health system, or some yet unknown influence.

That’s part of what makes it so hard to understand mass shootings. From one angle, they seem so unaccountable, like unpredictable and pointless acts of violence. Yet they’re also part of a broader trend, weirdly connected to an uptick in mass violence that may well have a deeper cause.