NEWTOWN, Conn. -- When Adam Lanza walked out of his house for the last time, he left behind firearms and knives and more than 1,600 rounds of ammunition, taking only four guns. They would suffice.
He loaded the weapons into his car, drove to Sandy Hook Elementary School, blasted his way into the building and within five minutes fired off 154 shots with a Bushmaster .223-caliber rifle. Having slaughtered 20 first-graders and six educators, he killed himself with a shot from a Glock handgun. He still had more than 100 rifle bullets at hand.
Warrants released yesterday provide the most insight to date into the world of the 20-year-old gunman, a recluse who played violent video games in a house packed with weaponry that was all too real.
The guns used in the shooting had all apparently been purchased by Lanza's mother, Nancy, with whom he lived, said prosecutor Stephen J. Sedensky III, in a statement accompanying the warrants.
She was found dead in her bed; Adam Lanza had shot her the morning of the massacre, Dec. 14. Authorities also found a gun safe in his bedroom and a holiday card from Nancy Lanza containing a check made out to her son for the purchase of yet another firearm.
"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's possible to determine a motive for the massacre, there may be clues in Adam Lanza's journals, which state police seized from the house and turned over to the FBI for analysis. But authorities say that so far no conclusions have been reached. Sedensky estimated that the investigation will be finished this summer.
Investigators at Lanza's house found a 7-foot pole with a blade on one side and a spear on another, a metal bayonet, three samurai swords, a .323-caliber bolt-action rifle, a .22-caliber Savage Mark II rifle and a .22-caliber Volcanic starter pistol.
They also found books about autism and Asperger's syndrome, as well as one with tabbed pages titled "Train Your Brain to Get Happy." Adam Lanza was said to have been diagnosed with Asperger's, an autism-like disorder that is not associated with violence.
News outlets reported previously that Lanza showed interest in other mass killings. Some, including The Hartford Courant, reported that he had a particular interest in Norwegian mass murderer Anders Behring Breivik, who killed 77 people in 2011.
A partial list of evidence found in the home of Adam Lanza and his mother Nancy:
More than 1,700 rounds of ammunition.
One Enfield Albian bolt action rifle, .323 caliber.
One "Savage Mark II" .22 caliber rifle magazine, 3 live rounds and 1 spent cartridge
One metal bayonet
Knife with a 12-inch blade and a sheath
Wooden-handle knife with a 7.5-inch blade and a sheath
Six-foot-10-inch wooden handled two-sided pole with a blade on one side and a spear on the opposite side
Three Samurai swords
The book "Born on a Blue Day: Inside the Extraordinary Mind of an Autistic Savant."
National Rifle Association certificates naming Nancy and Adam Lanza. (The NRA denies any connection between the Lanzas and the organization.)
Numerous paper targets
Book: "Train Your Brain to Get Happy," with pages tabbed off
Holiday card from Nancy Lanza containing a Bank of America check made out to Adam Lanza for the purchase of a C183 (firearm)
New York Times article from 2/18/08 of a school shooting in Northern Illinois University
Photographs with images of what appears to be a deceased human covered with plastic and blood
Box for military-style uniform from Adam Lanza's bedroom