There's still no scientific way to know who will become a mass shooter

A new report charges that there hasn’t yet been enough concerted research on what makes a person become a mass shooter.

Sandy Hook Elementary School responders. (Mario Tama).

It may be that the era of mass public shootings began way back in 1966 when two occurred within weeks of each other in Chicago and Austin. There have been 306 school shootings since 2013, or about one a week, according to Everytown. Each time such a tragedy occurs, we're first reminded of the easy availability of assault weapons followed quickly by blame assigned to the people—local police, psychologists, social workers—who failed to identify the perpetrator as a danger to their community. But this kind of hindsight is unfair. The truth is there's been amazingly little coordinated study of the psychology behind mass shooters and very little consensus as to what those warning signs might be. A new review of such research was compiled by sociologist Michael Rocque and criminologist Grant Duwe and is in the February issue of Current Opinion in Psychology.

Media finger-pointing exacerbates such lazy misconceptions and hysteria, so in the absence of methodical study, Roque notes, “Everybody's an expert on this issue, but we're relying on anecdotes."

(Photo: John Moore)

Mass public shootings: rampage shootings and school shootings

As defined by Rocque and Duwe, rampage shootings are mass shootings (generally defined as involving four or more victims), taking place in a public location, with victims chosen randomly or for symbolic purposes.

School shootings are any violent gun attack on another person occurring in a school.

Click image to jump to an interactive map of U.S. school shootings on Everytown's site. (Credit: Everytown)

The heartbreaking attack on Marjory Stoneman Douglas High School in Parkland, Florida on Valentine's Day was an example of both types of shooting.

Duwe tells Science News, “There is little good research on what are probably a host of problems contributing to mass violence," and he's not alone in thinking so. Another researcher criminologist, James Alan Fox, has been trying for a decade to get crime researchers to pay closer attention to the motivations of these killers. Criminologists may ascribe the same motives to a mass murderer as they would to other murderers, or consider them simply so psychotic that study of them would be beyond criminology. And in the U.S., gun violence is such a politically charged topic that there's been very little funding allocated for the study of it.

(Photo: Michele Eve Sandberg)

Absent widespread research on learning to identify potential shooters, individual experts have been trying to develop some helpful insights and predictors, and Rocque and Duwe compile some of the latest theories in their summary.

Possible risk factors

Mental illness

Obviously, it's too simplistic and unhelpful to simply pronounce each shooter as mentally ill and then move on to the next tragedy. Most mentally ill people are non-violent. Researcher Louis Klarevas, in his book Rampage nation: Securing America from mass shootings, finds that while 80% of mass killers have some form of mental illness—with mental illness and anger as immediate factors—it's more a "gateway" and not a trigger to action. Another analysis suggests that 60% of shooters have been diagnosed with mental issues. This is three times higher than the incidence of mental illness in the general population, so it's concerning, but it also means that a substantial 40% of shooters have not previously been diagnosed as having mental issues.


Nearly every mass shooter in recent times, 99%, has been male and some suggest a challenge to masculinity is a recent contributing factor in the decision to kill. Sociologist Michael Kimmel posits that mass shootings may reflect the “culture of hegemonic masculinity [that] encourages the use of violence to avenge a perceived challenge to their masculine identity." Intriguingly, most shootings occur in white rural areas where local culture encourages an unambiguously heterosexual form of masculinity.

Copycat contagion

Fame found.

In today's attention-hungry American culture, it's clear that becoming a shooter is a quick way to fame. Florida media coverage may also encourage potential shooters to become copycats, sometimes perhaps out of a feeling of identification with another shooter. Some experts have suggested that names of mass killers be withheld from media coverage so as not to risk glorifying them in the minds of dangerously like-minded individuals.

Deadly conditions

The trinity of violence

In his book Rampage nation: Securing America from mass shootings, Louis Klarevas cites a trinity of violence: three conditions that need to be in place for a shooter to commence an attack.

1. The availability of a weapon capable of killing many people in a short time
2. A motivated offender
3. A target or targets

Strain theory

This idea, described by Jack Levin and Eric Madfis in “Mass Murder at School and Cumulative Strain," sees the individual experiencing increasing levels of strain until he snaps. It describes a series of events that may lead to an attack.

1. Long-term strain, from bullying, troubles with employment or family
2. Uncontrolled strain, when the subject has no access to other people who can help relieve the growing strain
3. A specific strain of some sort, a loss or setback, sparks the idea of a shooting
4. Planning
5. Attack

A (de)pressing problem

(Photo: Joe Raedle)

Mass shootings are on the minds of many of us on a daily basis, especially those of us who are parents with school-age children. In 2018, wishing a child a good day upon being sent off in the morning includes the implied “please don't get killed." For the kids, it's a never-ceasing shadow of each day and their social interactions. Alongside common-sense gun-control regulations that protect children, a more aggressive and science- and data-driven assessment of what causes a shooter to shoot is beyond overdue.

A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source:

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source:

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source:

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

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