Unabomber Theodore “Ted” Kaczynski waged a solitary bombing campaign for almost two decades from a backwoods cabin in Montana, developing a unique and self-styled anti-technology ideology in near complete social isolation. He also bore little resemblance to most of today’s solitary attackers whose violence has, for the most part, been encouraged through like-minded online communities and enabled by how-to manuals on the internet. Some have even argued that it is time to retire the lone wolf moniker lest we aggrandize the actions of those who in essence are mass murders. However, the lone wolf terrorist label persists among those who study this phenomenon and seek to detect and prevent its occurrence.

Still Rare

Terrorist attacks by lone individuals are statistically rare and yet, as we have seen in the past few weeks, they can devastate communities and inflame public fears. The recent attacks, including lone armed gunmen in Louisville and Pittsburgh and the Florida-based singleton mail bomber, Cesar Sayoc, have once again demonstrated the power of a solo actor with malevolent intent. While Louisville and Pittsburgh suffered tragic outcomes, our law enforcement agencies, thanks to exceptional investigative work, identified and apprehended Sayoc before any of his devices detonated and before he could perfect his bomb-making skills.

The cluster of recent lone actor attacks also raises the specter of copycat attacks, a phenomenon observed by criminologists, usually among young males who are inspired by sensational publicity that surrounds mass murders and who exhibit a combination of severe mental illness, criminal records, or a history of violent behavior. However, lone wolf terrorism researchers Mark S. Hamm and Ramón Saaij found that of the 12 lone wolf terrorist copycat attackers they studied, only three were young and only three had mental illnesses. Motive appears to be the biggest difference between copycat mass murderers and copycat lone wolf terrorists. Copycat mass murderers seek fame for themselves, while copycat lone terrorists want to further a political cause.

More in Common with Mass Murderers

Developing a reliable personality profile of a typical lone terrorist has always been difficult. Such profiling has also not been particularly helpful to law enforcement because the most common traits exhibited by these individuals—male, socially isolated, previous brushes with the law—are so common in the general population that they are useless in trying to pinpoint who is or will become a violent lone actor. However, University College of London researchers Paul Gill and Emily Corner were able to identify several common characteristics among a database they compiled of more than 119 lone wolf attackers since 1990 in the U.S. and Europe, which they compared against a similar set of group-based terrorists. For instance, the lone wolf terrorists studied by Gill and Corner demonstrated a higher incidence of documented mental illness than those who were group-based terrorists. They also found that for many lone wolves, personal grievances were as much a motivation as politics. More than half of the lone actors also experienced social isolation. Gill and Corner concluded that the lone wolf terrorists appeared to have more in common with apolitical mass murderers than with group-based terrorists. One example that comes to mind is Omar Mateen, who murdered 49 and wounded more than 50 people in the Orlando Pulse gay nightclub shooting in 2016. Mateen’s ex-wives and acquaintances described him as mentally unstable and violent, and he appears to have been motivated as much by anguish over his own sexual orientation as Islamic terrorism.

Difficult to Detect and Pre-empt

The incidence of lone terrorist attackers has continued to increase in the U.S. and internationally, and the Washington Post recently cited statistics to indicate that mass murders are a near daily occurrence in the U.S. Nonetheless, terrorist attacks by lone actors are still relatively rare and much less common than group terrorist attacks. Actions by individuals have also historically been much more difficult to detect and prevent primarily because the perpetrators operate on their own and are not communicating their intent with collaborators. The tools of intelligence agencies and law enforcement, including undercover sources and intercepted communications, are much less effective against an individual who is not communicating his plans and intentions to others. White supremacist leader Louis Beam recognized this when he advocated the use of small cells to prevent detection by law enforcement in his 1983 essay “Leaderless Resistance.”

Technology is also an increasingly important element in today’s lone actor terrorism. Whether using the internet as a source of inspiration, how-to advice, or to forge connections to like-minded extremists, today’s lone wolves are increasingly reliant on the internet, and increasingly able to use new technologies to mask their identities online to avoid detection. However, even with the prevalence of online forums where hate-speech and pro-terrorist sentiment flourishes, distinguishing between the thousands of individuals accessing and posting content on these websites and the handful who may at some point act on their feelings is nearly impossible. Former FBI Director James Comey described it as “looking for needles in a nation-wide haystack.” An attacker’s online profile may provide clues to an attacker’s motivation or information that could be useful to law enforcement authorities, but generally only after an attack, to narrow down and zero-in on the perpetrator.

Furthermore, posting such content in most cases is not against the law and is usually protected by free speech and privacy laws in the U.S. and most Western democracies. Some might say that the Florida mail bomber Sayoc was hiding in plain sight and question how he could have been missed. His truck, in which he was living, was plastered with anti-Democratic Party stickers, and his online tweets hinted at malevolent intent. Such activities alone do not, however, constitute probable cause to justify search warrants or surveillance. In another example, Omar Mateen came briefly under FBI scrutiny several years before the Pulse nightclub shooting after co-workers expressed concern about his possible links to Islamic terrorist groups. The FBI looked into the allegations, but found insufficient evidence of terrorist links to continue the investigation of Mateen. The high cost of mounting surveillance and deploying investigative resources is another constraint, and our law enforcement agencies must constantly prioritize where to deploy resources.

Greater efforts by social media companies to identify, shut down, and erase objectionable sites and content, while done with good intent, can also make it harder for governments and law enforcement agencies to identify and track persons of interest.

One potential opportunity to identify and pre-empt lone attackers is through more effective engagement with communities and those in a position to learn in advance of these attacks. Mark S. Hamm and Ramon Spaaig found that more than 75% of lone wolves tell another person, usually a friend or family member, about their intentions or even post their plans on social media. Unfortunately, this information is rarely reported to authorities. For instance, Dylann Roof, the perpetrator of the Charleston Emmanuel AME Church shooting in 2015, posted white supremacist content on his Facebook page and talked to acquaintances about mounting an attack on a local college. A week before the massacre, Roof confided to a drinking buddy details of his plan for a shooting rampage. However, his friend dismissed his comments as drunken bluster and did not warn the authorities.

Public Health Model: A Strategy for Prevention

In the summer of 2016, the National Security Critical Issue Task Force (NSCITF), comprised of a small group of graduate students in the Security Studies Program at Georgetown University’s School of Foreign Service, took on an examination of the current “state of the art” for countering violent extremism. The NSCITF applied a public health prevention approach to the process of radicalization to extremism and ultimately to violent action. Adopting the public health sector’s methodology and framework, the NSCITF applied primary, secondary, and tertiary stages of disease prevention to countering violent extremism (CVE).

The public health framework has the potential to prevent terrorists and mass murderers also. In public health/medical practice, tertiary prevention involves providing treatment for an illness, i.e., diabetes, high blood pressure, or high cholesterol, after it is diagnosed (notice all of the ads during prime news time). Secondary prevention deals with the early vulnerabilities within a population to prevent or address causative factors such as family history, poor diet/increased weight, or lack of exercise among kids. Primary prevention strategies include larger-scale programs such as early health education, immunizations (flu), pollution control, and water fluoridation. Primary prevention is also directed at the general population before the onset of disease.

In thinking about the prevention of terrorist and mass murder events, tertiary prevention would refer to interdiction, arrest, and prosecution of individuals plotting an attack, and, in the worst case, tertiary prevention is our response after the incident has taken place. Secondary prevention consists of community engagement and efforts directed at a perpetrator who at this stage is showing signs of emerging violent or terrorist tendencies and/or involvement in minor incidents of violence but has not yet crossed over to plotting a major action. Secondary prevention might also include adopting common sense laws that enable law enforcement to take action in response to troubling behaviors. This could include, for example, removal of guns from a home after domestic violence accusations or involuntary hospitalization or community treatment commitment for evaluation after threats of violence. Primary prevention includes positive education opportunities and job training as well as accessible, affordable, and competent mental health services.

Re-Thinking Prevention

Failure at primary and secondary prevention creates the need for tertiary options. While only a very small number of individuals will cross the line and make the decision to design and execute an attack, the cost can be devastating. If we are fortunate enough to get an early warning of an attack, the ideal strategy will be intervention/interdiction. Only by making greater investments, however, in primary and secondary prevention can we hope to reverse the rising rates of violent lone actors engaged in mass murder.