The original paperback version of Helter Skelter, Vincent Bugliosi and Curt Gentry’s true-crime blockbuster about the Manson killings, contained, on its very first page, a lurid all-caps warning: THE STORY YOU ARE ABOUT TO READ WILL SCARE THE HELL OUT OF YOU. I stumbled upon this book in the latchkey-kid ’80s, at a far too young age, and it haunted me for years. Rereading it as an adult, I was no less shaken by its sinister synthesis of subject and craft. Equal parts police procedural, social history, and epic courtroom drama, Helter Skelter is a ghastly L.A. noir whose real-life facts defy belief to this day.

Published five years later, The Executioner’s Song, Norman Mailer’s account of double murderer Gary Gilmore’s crimes and subsequent wish to forgo any appeals and move ahead with his death sentence, is a work of even greater scope. Mailer, accessing some superhuman tool kit, brought the full range of his gifts to the creation of this 1,050-page masterpiece. Though entirely factual—and indeed a product of much research and journalistic rigor—Mailer called the work a “true-life novel.”

These books—along with Truman Capote’s In Cold Blood, Ann Rule’s The Stranger Beside Me, and Dave Cullen’s Columbine, to name just three—belong on a higher shelf than their distant cousins in the genre, the mass-market shockers patched together and published at warp speed. The best true-crime books transcend the sheer horror of their subject matter to elucidate larger issues—of psychology, of culture—and in doing so become lasting art.

Åsne Seierstad’s One of Us: The Story of Anders Breivik and the Massacre in Norway belongs on the shelf of classics. It tells the harrowing tale of Anders Breivik, the Norwegian man who, in an anti-Islamist fervor, committed one of the deadliest mass killings in history.

On July 22, 2011, Breivik, then 32, drove a rented van into Oslo’s government quarter, parking in front of the prime minister’s office. He reached back and lit the fuse on his homemade bomb. Moments later the bomb exploded, killing eight and wounding many more. By then Breivik, dressed as a police officer, was in another van, en route to Utøya, a small island where a summer camp for the youth wing of Norway’s Labor Party was in session.

Despite an eyewitness who phoned the authorities almost immediately, giving them the new van’s make and registration number, Breivik easily evaded detection. The ferry captain, believing Breivik to be police, drove him over to Utøya, where the gunman opened fire. As the woefully unprepared Oslo authorities scrambled to react to the initial explosion, Breivik stalked the island, shooting, for more than an hour. He killed 69 people, most of them teenagers.

The long chapter chronicling the attack makes for overwhelming reading. Seierstad’s you-are-there reconstruction is unsparing in its degree of detail; at times I felt almost faint. But Seierstad has in mind far more than the atrocity, following the perpetrator from childhood on. Breivik spent much of his life searching for a sense of belonging. He cycled through various identities and whims: aspiring graffiti tagger, businessman, and Freemason; later, hardcore video-gamer and right-wing ideologue. Failing to achieve the level of success he desired in any of these, Breivik named himself commander of a one-man army and methodically planned for warfare.

Seierstad also includes the life stories of some of the victims, whose youthful passion for inclusiveness and civic engagement only makes the inevitable attack harder to bear. In a pair of throat-clenching passages late in the book, two Utøya survivors face Anders Breivik at his trial. One of them, Viljar Hanssen, was shot five times, including once in the head. He lost an eye and a hand. The poise he displays before his attacker is remarkable. Here is the end of his testimony:

“I think you’ve finished, then,” said judge Arntzen.
“Fabulous,” said Viljar.
He stood up, spun on his heel and went. Out.
It was almost summer. 
He had his life in front of him. He could walk, sit and stand. He had his wits about him. And many people to live for.”