The extent of Adam Lanza’s abject loneliness, the intensity of his scorn for the world, his interest in pedophilia, his astounding list of daily grievances, the reach of his obsession with mass murder — some of the granular details of the Sandy Hook shooter’s last years have been elusive.

Until now.

More than 1,000 pages of documents obtained by the Hartford Courant from the Connecticut State Police, including hundreds of pages of Lanza’s own writings and a spreadsheet detailing the gruesome work of 400 perpetrators of mass violence, bring into sharper focus the dark worldview of a 20-year-old who shot his mother four times as she slept and then killed 20 first-graders and six educators before killing himself at Sandy Hook Elementary School in Newtown, Conn., on Dec. 14, 2012.

Diagnosed as a child with a sensory disorder and delays in speech, he would exhibit a quick mind for science, computers, math, and language. The few acquaintances he had as a teenager came from video game arcades and online gaming chatrooms. The newly released writings express a wide range of emotions and rigid doctrine, from a crippling aversion to the dropped towel, food mixing on his plate and the feel of a metal door handle, to a deep disdain for relationships, an intolerance of his peers, a chilling contempt for anyone carrying a few extra pounds, and a conviction that certain aspects of living are worse than death.

At the same time, he also predicted that he would make a good father, because he would treat children as independent little people who just didn’t know a lot yet. In a memo-style letter to his mother, Nancy, who lived in the same house, he encouraged her not to be dejected about her life.

These documents, which had been kept from the public until now, were part of the mass of writings, records, and computer files seized by detectives from the Lanzas’ home after the murders. The Courant mounted a five-year quest to obtain the unreleased documents, eventually winning an appeal before the state Supreme Court.

From the journal entries, school assignments, an erstwhile screenplay involving pedophilia, education records, and psychiatrists’ reports spanning about 15 years of Lanza’s life, several parallel themes emerge, each moving inexorably toward the day when the emaciated loner, crippled by obsession, scornful of most other people, and fascinated by the human capacity for murder, committed his unspeakable act of violence. Some of the writings and psychoanalysis are dated. Many are not.

The documents released by the state police aren’t in chronological order and it’s unclear when Lanza wrote many of them. A number of them are unsigned, though several were downloaded from his computer where they had been stored on his desktop. Lanza removed the hard drives from his computer and smashed them to pieces. The FBI was tasked with trying to retrieve data.

One thing becomes clear as the additional records are examined — Adam Lanza, from the age of about 3 until he was 18, was never off the radar of people who orbited around him — his parents, the teachers and counselors in the schools he attended, the psychiatrists who later tried to figure out what was happening with him. It is evident now that no single person grasped the full picture of what he was becoming.