Since the 1960s, the frequency of mass shootings in the United States has increased by over 10,000 percent.

Among the shooters, there are commonalities—social isolation, feelings of persecution, psychotropic drug use, obsessive playing of violent video games (like Call of Duty or World of Warcraft), etc.—that experts will, in every aftermath, desperately try to collate and quantify with the hope of achieving some understanding of a phenomenon that has become appallingly familiar in our culture.

But however much the data on shooters are fed into algorithms and weighed against behavioral profiles and generally subjected to all manner of scientific methodology, the concerned citizen, expert or layman, will quickly know the limit of such inquiry. Because up until the moment a young misfit decides to pull the trigger, one can empathize with social isolation, or feelings of persecution, or the vicissitudes of being on mood stabilizers, or the adrenaline rush of graphic video game violence. Up until that moment, one must concede that just because a person fits the profile, and maybe even keeps a goodly stash of firearms in the house, that person is not necessarily on the brink of slaughtering his or her peers in a hail of gunfire. The fact is, those who fit the profile and never commit a crime far outnumber those who do.

Yet parsing the data feels like a moral duty, fruitless as it may ultimately be. We would be remiss as a culture if we didn’t make a systemized attempt to pursue what Stephen and Joyce Singular, in their book The Spiral Notebook: The Aurora Theater Shooter and the Epidemic of Mass Violence Committed by American Youth, would call a “little push”: the element—elusive, but suggestive as dark matter—that turns a young person from troubled to murderous.

The focus of The Spiral Notebook is James Holmes, who in July 2012 dyed his hair Joker-orange, decked himself in military grade combat gear, and murdered a dozen people at a midnight showing of the filmThe Dark Knight in Aurora, Colorado. The Singulars are able and enthusiastic reporters, providing detailed depictions of the event, the lead-up to it, the emergency response, and then, to their frustration, a judicial process assiduously withheld from the prying eyes of the media.

The titular spiral notebook refers to the volume holding Holmes’s musings before he committed his act, what one might call his manifesto. To the Singulars, it represents both a psychological “Rosetta Stone” of insight into why he did what he did, and also a symbol of a broken judicial system that would keep such a document from a public desperate for insight. The latter gives them ample exercise. Holmes is certainly guilty of the crime, so his defense team’s objective is to save him from the death penalty. Their strategy is to repeatedly delay the trial date, which they do successfully, while devising an insanity defense. The insanity plea should have been a boon to the media because it would nullify the doctor-patient confidentiality laws that required the notebook’s suppression (since Holmes sent it to his psychiatrist hours before his rampage).

But while the new plea made the notebook admissible in court, the judge, much railed-against for the secrecy he fostered, continued to withhold it from public view. Because of this, the Singulars come to regard Holmes’s notebook as some untouched key, a look into the psyche of a mass shooter heretofore unseen.

Would the pages reveal what happened to the defendant after he moved to Aurora? And what had changed between the winter of 2012 […] and the late spring and early summer of that year? Would the notebook […] document his slide into insanity or show the intricate designs of a premeditated killer? […] Could one be fully functional in society and insane at the same time? […] Would the notebook finally provide some answers?

The exasperating truth is that other works exist in this genre, but they do little to advance our understanding of the transition from disaffected youth to mass killer. The manifesto of Isla Vista shooter Elliott Rodger is 144 numbingly repetitive pages in which Rodger recounts his failures to entice women to sleep with him until deciding they are fundamentally evil and must be punished with death. If one didn’t wince at the prospect of reading the 1500-page manifesto of Anders Behring Breivik, the Norwegian who methodically killed 69 people at a Workers’ Youth League summer camp, one may conclude, as Karl Ove Knausgaard did in a recent New Yorker piece, “Breivik’s childhood explains nothing, his character explains nothing, his political ideas explain nothing.” It would seem that even if a killer says why he killed, most of us still wouldn’t understand it.

Without access to the notebook, the Singulars turn to the shooters’ peers, and here they find their most useful insights. Woven throughout The Spiral Notebook are quotations from members of the “American youth” in question, including the Singulars’ son, whose “formative years in Denver were bookended by two mass tragedies,” Columbine and Aurora. After Aurora, the Singulars knew they had a story they wanted to pursue. The court’s gag orders proved an impediment to their forensic analysis, but the seed of a newer, and perhaps more useful, angle had sprouted in their own home. Asking their son Eric for his thoughts on the shooting, they encountered disturbing reticence: “You don’t understand how I grew up,” he told them. “You just don’t get it, […] No offense, but you’re too old.”

Does the failure to understand mass murder committed by young men equate to a failure to understand the culture around them? One veteran journalist quoted by the Singulars exclaims, “If I hear one more teenager say that he or she understands why those two kids did what they did at Columbine, […] I’m going to scream.” Throughout these interviews, an assumed incomprehensibility entered a new light: are mass shooters somehow relatable to their Millenial peers? Says one twenty-one-year-old man, “Sometimes I just want to blow. The only thing that stops me is my own sense of self-control. Take that away, and I just don’t know what would happen.” The other interviewees recount overlapping narratives of endemic drug use, school bullying, the pressures of a consumerist society, and obsessive playing of violent video games. Through their collective words, the pieces of a particular world come together, a world that is inhabited by both the victims and the perpetrators. Theirs is a common despair. Regardless of public access to Holmes’s spiral notebook, the manifesto exists in the minds of all young people immersed in a violent, drugged up, materialistic world. And they are happy to tell us about it.

Now, after countless delays, James Holmes’s capital trial is under way, and the spiral notebook has been made available to the media. The salient implication is a legal one: it seems Holmes was perfectly able to distinguish right from wrong. But the unfortunate message for the Singulars, and for the rest of us pining for an answer from the mind of a mass killer, echoes Knausgaard’s conclusion about Breivik, and comes from Holmes’s own pen (via recent CNN coverage of the trial): “The message is there is no message.” We look, then, to the masses, where murder is still an aberration, but despair is not.