Police in the United States have released thousands of documents related to their investigation into the killing of 26 people at a school in Connecticut in December 2012.
The report reveals new facts about the life of gunman Adam Lanza, 20, said to have suffered from mental health issues. Many of the documents detail his obsession with mass murders.
Lanza turned a gun on himself after opening fire with a semi-automatic rifle at Sandy Hook Elementary School in Newtown and killing 20 children and six adults.
Before driving to the school, he shot dead his mother at the family home. She had bought him the weapons used in the rampage.
Last month Connecticut state police published a summary of their findings, showing that Lanza had "an obsession" with the 1999 Columbine massacre, during which two teenagers killed 12 students and a teacher.
Investigators also found that Lanza had acted alone and planned the shooting, which took less than 11 minutes.
The final report contains evidence that Lanza's mother discussed her son's "disabilities" with a friend the day before the Sandy Hook attack.
The findings also reveal autopsy reports and new information about how the shooting unfolded. The files were heavily redacted to protect students' identities and withhold gruesome details.