Sandy Hook Shooting: Police Release Newtown, Connecticut Files Connecticut police released a trove of documents and files Friday from the investigation into last year's Sandy Hook Elementary School shooting in Newtown that left 20 children, six adults and the gunman dead. The release of thousands of pages of documents could shed some new light on a case that has already been explored exhaustively, but it also effectively closes the book on one of the worst school shootings in American history. A report published last month at the conclusion of the investigation said authorities could not answer the painful question of why 20-year Adam Lanza killed his mother and then 20 children and six adults at the school in Newtown before turning the gun on himself. But the investigation report provided a detailed lens into Lanza's life and into the tragic events last December. Recordings of 911 calls from that day were also recently released. The files released online Friday include thousands of pages of documents, photos, videos and recordings of 911 calls obtained over the course of the investigation, some of which was described in or released alongside last month's report. Investigators, who gathered evidence from Lanza's home and interviewed his family, teachers, and others around him, found that Lanza had mental health problems as well as a fascination with mass shootings, though he displayed no "threatening tendencies," according to last month's report. "The investigation of this incident is unparalleled in the one hundred and ten year history of the Connecticut State Police," Reuben Bradford, commissioner of the state Department of Emergency Services and Public Protection, wrote in a letter accompanying the documents released Friday. "I hope that the release of this report, though painful, will allow those who have been affected by it to continue in their personal process foe haling, and will provide helpful information that can be put to use to prevent such tragedies in the future," Bradford wrote. Bradford said in the letter that the investigation is closed and would be reopened "in the unlikely event" that substantive new information arises. Some information, including names of children and witnesses and images depicted the deceased, has been redacted from the public documents according to law. The documents can be seen here. MORE: What We Learned From The Investigation On The Sandy Hook Shooting