Connecticut released the Sandy Hook summary report yesterday (PDF). It contained no significant surprises, but did include one eye-opening detail.
The report confirms that Lanza’s mother was murdered with 4 shots from a Savage Mark II .22LR rifle in their home. It confirmed that Adam Lanza carried out his attack exclusively with a Bushmaster XM15-ES2 carbine, and that his took his life with a single shot from a Glock 20 10mm pistol, and that the Sig P226 9mm pistol found with his body was never fired at all.
It also confirmed that Lanza chose to leave a Saiga 12-gauge shotgun in his car, which was later recovered by police.
[For those insistent that something else/more/dramatically different occurred, I would direct them to author and gun expert Michael Z. Williamson's treatment of those theories.]
A very interesting detail revealed in the report is the “what might have been” if some faculty and staff members of Sandy Hook Elementary school had been trained and equipped with firearms, particularly one staff member.
It seems probable that Principal Dawn Hochsprung and school psychologist Mary Sherlach and two other staff members injured in the very beginning of the assault did not recognize Lanza’s breaching of the school as an armed assault until it was too late for them to have had any effect on the outcome, even if they had been carrying concealed firearms.
Another school staffer, however, quickly recognized the sound and smell of gunfire, as noted in the final paragraph before the “Response” section of the document begins.