It’s not so easy to count mass killings

Two years ago this month, a particularly horrific mass killing took place in a Newtown, Conn., school. We’re still struggling with how we cover these crimes:

— In September, an FBI report on so-called “active shooter” cases was widely misreported to show that “mass shootings” were increasing. A federal definition shared by several agencies defines “active shooter” as “an individual actively engaged in killing or attempting to kill people in a confined and populated area.” For its report, the FBI make two tweaks: To include cases where more than one person was shooting and to drop “confined” to include outdoor events. It’s worth pointing out that many of these cases don’t meet the FBI’s definition of a mass killing: four or more dead, not including killer(s).

The FBI just wanted tactical insight, so it also excluded whole categories of potentially qualifying events: “Specifically, shootings that resulted from gang or drug violence—pervasive, long-tracked, criminal acts that could also affect the public — were not included in this study. In addition, other gun-related shootings were not included when those incidents appeared generally not to have put others in peril (e.g., the accidental discharge of a firearm in a school building or a person who chose to publicly commit suicide in a parking lot).”

Wrote the authors: “The study does not encompass all mass killings or shootings in public places and therefore is limited in its scope.”

Resulting headlines at major news organizations: “Mass Shootings on the Rise, FBI Says”;  “Mass Shootings on the Rise, New FBI Study Shows”; “FBI: Mass shooting incidents occurring more frequently”; “FBI study: Deaths in mass shootings increasing.” (Search users beware: A recent check finds many still uncorrected stories on the Web.)

MK_20141218— We continue to update USA TODAY’s interactive graphic of mass killings, published a year ago. We use the FBI’s definition. This year we’ve counted 23, a bit below the average of 30 from 2006-13. (More on that in a minute.) Most weren’t big news outside the towns where they occurred. Typically, they involved a man targeting family members and acquaintances. Most involved guns but a handful did not. None involved semiautomatic rifles, although police haven’t revealed the weapon in a few cases. Almost half of the suspects were found dead or were killed by police. In all, 104 victims were killed, 12 more wounded.

It was, sadly, a typical year. The ingredients were many, familiar and resistant to easy fixes: broken families and relationships, poverty, drug abuse, ubiquitous legal handguns, inadequate mental health care systems.

— In 2015, reports of “mass killings” may increase simply because a 2013 federal law set a broader definition: “3 or more killings in a single incident.” That’s one reason the FBI compiled its “active shooter” report: The law allows the Justice Department to assist local authorities in such cases.

So how many mass killings would that broader definition add to the 25 to 30 each year in which four or more are killed? For the year that ended in June, USA TODAY scoured news reports and cross-checked each possibility in the FBI’s incomplete Supplementary Homicide Report.

We found 76 triple homicides. For the incautious, that would be “a 300% increase!”

We look forward to the headlines. — Paul Overberg