STRIP MALLS, MOVIE theaters, schools, grocery stores — the images in Speaking Is Difficult, the new film by Field of Vision co-creator AJ Schnack, are ordinary but serene. Wherever we live, these are the places where we routinely expose ourselves to the wider world. The film punctures this calm familiarity with grainy audio documenting past traumas. The details we can ascertain from these 911 recordings are sparse — a white male shooter, an unknown number wounded — but we all know how to fill in the blanks. In one sense, we’ve seen this movie before. As the title suggests, these public massacres are hard to talk about. This is not just because they are frightening, horrific, and unpredictable, but also because in empirical terms we just don’t know that much about them. “There is a dearth of comprehensive, authoritative data on multiple-victim homicide incidents, either committed wholly or partially with firearms,” the Congressional Research Service lamented in its July 2015 report on what have recently become known as “mass shootings.” Given all that we don’t know, how can we hope to answer Gabrielle Giffords’s call to action at the end of Speaking Is Difficult, to prevent the kind of killing that very nearly took her life?

As the CRS was preparing its report, amateur researchers, frustrated by the lack of information about these seemingly regular massacres, began to take matters into their own hands. In the first major real-time effort to compile a record of every mass shooting in the United States, a group of anti-gun Reddit users found that these events occurred once per day, on average, in 2015. The Washington Post picked up their findings in August, and for the rest of last year major news outlets ran headlines declaring that mass shootings were happening every day in the United States. But was it true? That depends on how you define “mass shooting.” Because these researchers counted any event in which four or more people were shot, the vast majority of their database entries appear conceptually distinct from the largely random public killings documented in Speaking Is Difficult. They include armed robberies, gang shootouts, and familicides. As of the end of last year, shootings in private residences accounted for more than two-thirds of the entries, and the majority of cases involved the murder of a family member or intimate partner. Very few of the shootings made the national news. For the past three years, researchers at Mother Jones have been maintaining a more precise database of mass shootings in the United States, one that uses a number of criteria to exclude the huge majority of cases involving domestic violence, gang activity, and other interpersonal conflicts. As of March 2016, they have identified 75 mass shootings since 1982. That 34-year total is less than a quarter of the number news outlets regularly claimed were occurring in 2015 alone. While this lower figure might seem to deflate claims that mass shootings in the United States are on the rise, a statistical study of the Mother Jones database by a team of researchers from Harvard’s School of Public Health found otherwise. Their analysis determined that although the frequency of public mass shootings remained relatively steady for almost 30 years beginning in 1983, the frequency tripled in 2011, from an average of once every 200 days to once every 64 days. Given this finding, recent media pronouncements that we live in an “age of mass shootings” do not seem so far fetched. Although the Mother Jones dataset provides some evidence for the previously inchoate sense that these public shootings constitute a kind of epidemic, it does not bring us much closer to understanding how we might prevent such massacres. The statistical method used by the Harvard researchers assumes that some underlying process is responsible for the frequency of shootings, and the point is to correlate the moments when the frequency changes — in this case, late 2011 — with real-world events that may have caused the change. For example, a point in time at which a certain surgical error becomes less frequent can be correlated with the introduction of a new sterilization method. But is it possible to identify an underlying process responsible for America’s mass shootings? The Harvard researchers themselves acknowledge that the number of potential variables in play makes answering this question nearly impossible, at least for now. However their findings do allow them to cast aspersions on some popular explanations for the rise of mass shootings, given that there were no widespread changes to mental health or access to guns in late 2011, when the frequency of shootings tripled. For these and other reasons, the researchers are skeptical that universal background checks would be a decisive deterrent. And research shows that a renewed assault weapons ban would have almost no discernible impact. Psychological profiling does not get us much further. While mass shooters tend to be white, male, and alienated, those traits in combination produce so many false positives that they have no predictive value.

Photo: James Palka/AP