Who bombed the Boston Marathon? While the FBI hunts for suspects and "persons of interest" in this case, an influential terrorism expert says that law enforcement has learned much about the kind of person, or persons for whom the 1,000 F.B.I. officials may now be searching.
No one yet knows whether the Boston attack is the work of a lone lunatic, a domestic extremist or right-wing hate group, a domestic or foreign jihadist cell or still anonymous others.
But if the attack turns out to have been directed or inspired by extremist Islamists – and that is still a big "if" -- Brian Jenkins, senior adviser to the president at RAND, widely regarded as a pioneer of terrorism research, says that previous jihadist attacks on American soil suggest that the culprit is likely to be a male American citizen, slightly older than the average convicted criminal, for whom Islam as a religion is less important than the search for adventure and a desire to be part of a historic "epic struggle."
He bases this conclusion on a new analysis of 41 Al Qaeda directed or "jihadist"-inspired plots in the U.S. that have resulted in 104 criminal cases in American courts involving 204 people since September 11th.
Based on the patterns in these cases, he said in an interview, the perpetrator would most likely be a "malleable youngish male, a loner, a bit of a loser." And he is more likely than not to be an American.
Jenkins' data show that 74 percent of those involved in these jihadist plots were U.S. citizens, 49 percent of whom were born in the U.S., 29 percent of whom were naturalized citizens. One quarter were born with non-Muslim names,strongly suggesting they were converts to Islam.
Some 68 percent of the 41 plots were planned by a single individual – not a "lone wolf," says Jenkins, but what he calls a "stray dog." Lone wolves, he says, are "determined renegades" who often demonstrate aggressive behavior and hunt outside the pack. American jihadists, by contrast, "bark and brag," but they are "skittish" at "sniff at the edges." Their barking rarely results in actual bites.
Only fourteen of the 41 plots had what Jenkins calls "mature operational plans." Ten of the 14 were FBI stings. Jenkins calls most of the plots "immature and amateurish." Only three resulted in actual attempted attacks, two of which caused casualties.
On average, jihadists were 32 years old; their median age was 27 – slightly older than the comparable incarcerated criminal population, between 18-24, Jenkins says.
A quarter of them have never finished high school; 22 percent have high school diplomas. Thirteen percent have college degrees; six have postgraduate degrees. Forty percent of them have gone to university -- for a time. But these 204 men were more likely than the average American college student to drop out, in their cases, to pursue jihad.
Contrary to popular perception, most of the foreigners involved in these plots have not been Arab. "Somalis and Pakistanis predominate," according to a slide in Jenkins' presentation. The same is true for attacks in Europe, where a disproportionate number of plotters have been Somalis, Pakistanis, and also Algerians.
The pursuit of jihad is less an expression of religious belief than a "conveyor for individual discontent," he says. Religion, per se, is of less importance than their search for adventure and camaraderie, their desire to join a warrior elite, a secret army, and their yearning to escape situations of personal discontent. "Their lives suck," Jenkins says.
Jenkins says he has been reassured somewhat by the data he analyzed for a presentation at a terrorism conference last month in Singapore.
The campaign by Al Qaeda and like-minded groups to recruit Americans to their cause has had very few takers, he concludes.
He calls such recruitment levels among the millions of Muslims in America "a very low yield." "There is no army of sleepers, no vast Muslim underground here," Jenkins says. Despite the proliferation of what he calls "retail outlets" for militant recruiting, such as the on-line magazine, Inspire, (whose editor was killed in a drone strike in 2011) and jihadist internet web sites, "Al Qaeda isn't selling a lot of cars these days."
The organization itself has faced devastating pressure. Its major training camps have been destroyed since 2001; its once easily accessible camps have been dispersed. Recruits are increasingly less competent and well-trained. Internet instruction has proven to be no substitute for hands-on-training.
Morocco, Saudi Arabia, Jordan, Turkey, and Indonesia have all dismantled significant Al Qaeda networks.
Al Qaeda's "core" or central leadership has been decimated by drones and arrests. Enhanced cooperation among law enforcement and intelligence officials throughout the world has made Qaeda's operational environment far more hostile.
Many plots have been thwarted or foiled – 17 since 9/11 in New York alone. There has been no significant jihadist terrorist attack in the West since 2005, Jenkins says. Compare that to the 1970's, when the nation suffered an average of 50-60 bombings a year, none of them Islamist.
Al Qaeda's recruiting efforts in the U.S. and encouragement of what he calls "do it yourself terrorism" are failing, he says. High conviction rates (nearly 100 percent) and lengthy prison sentences (between 25 years to life) has further discouraged would-be jihadis.
Jenkins findings mirror those of Charles Kurzman, a sociologist at the University of North Carolina at Chapel Hill and researcher at the Triangle Center on Terrorism and Homeland Security.
In a much-cited study published last year, Kurzman called the threat posed by homegrown Islamic terrorists "tiny." His report, "Muslim-American Terrorism in the Decade Since 9/11" found that the jihadi message had little appeal to American Muslims, and that levels of both planned attacks and financial support for jihadist causes have declined since 9/11.
Jenkins cautions, however, that while the threat of Islamist terror has become more diffuse, it has not disappeared. Al Qaeda and other jihadist groups remain determined to strike and capable of strategic patience.
Though smaller and often less lethal, homegrown terrorist attacks are often more difficult to prevent, and in some cases, to solve. "The individuals involved in such plots remain dangerous and potentially lethal," says Jenkins. "But they won't bring down the republic."