Shocking new records reveal the huge arsenal available to the Sandy Hook gunman - but give no sign of why Adam Lanza shot his way into the school and massacred 20 young children and six adults.
Warrants, released after a judge's order to seal them expired, give the clearest view so far into the troubled world of Lanza, 20, a recluse who played violent video games in a house packed with weaponry that was all too real.
When he walked out of his house for the last time, leaving his mother shot dead in bed, he left behind firearms and knives and more than 1,600 rounds of ammunition - taking four guns with him.
The December massacre at the primary school in Newton, Connecticut, brought the issue of gun control back into the national spotlight. President Barack Obama called the shooting the worst day of his presidency, and has urged politicians to support a key Senate vote next month on safety measures already weakened by political concerns and gun-lobby opposition.
All the weapons used in the Connecticut shooting had apparently been purchased by Lanza's mother Nancy, said prosecutor Stephen Sedensky, in a statement accompanying the warrants.
In just five minutes, Lanza fired 154 shots with a Bushmaster .223-calibre rifle, before killing himself with a shot from a Glock handgun. He still had more than 100 rifle bullets at hand. Authorities also found a gun safe in his bedroom and a holiday card from his mother containing a cheque made out to him for the purchase of another firearm.
Connecticut governor Dannel Malloy expressed incredulity over the access Lanza had to the cache of weapons. "There are parts of this story that are unfathomable," he said. "How anyone would have maintained that household that way is difficult to understand."
If it is possible to determine a motive for the massacre, there may be clues in Adam Lanza's journals, which police seized from the house and turned over to the FBI for analysis. But authorities say that so far no conclusions have been reached. At the Lanza house, investigators found books about autism and Asperger's syndrome, as well as one with tabbed pages called Train Your Brain To Get Happy. Lanza was said to have been diagnosed with Asperger's, an autism-like disorder that is not associated with violence.
But the warrants also reveal an intense interest in weaponry and violence. Investigators found a metal bayonet, three samurai swords, a .323-calibre bolt-action rifle, a .22-calibre Savage Mark II rifle and a .22-calibre Volcanic starter pistol. Literature seized from the house included a news article on a 2008 shooting at Northern Illinois University and a National Rifle Association guide to pistol shooting.
In a duffel bag, investigators found ear and eye protection, binoculars, numerous paper targets and an NRA certificate that belonged to Adam Lanza, although the NRA said Lanza was not a member.