Danbury State’s Attorney Stephen J. Sedensky III, officially closed the investigation of Adam Lanza, the sole mastermind behind the December 14, 2012 massacre at Sandy Hook Elementary School in Danbury, Connecticut. Lanza, 20, entered the school by shooting eight rounds through a window, letting himself inside the building where he would ultimately kill 26 people. The mass shooting was the second-worst in U.S. history, taking the lives of 27 people, including Adam’s mother, six school personnel, and, unfathomably, 20 first-grade children.

From the time Lanza entered the school until he shot himself was barely 11-minutes – but they are 11-minutes of the worst horror imaginable. The disturbed young shooter killed 20 six-year-old children with a high-powered Bushmaster .223. Officials say that Lanza, who weighed only 112 pounds, carried 31 pounds of ammunition into the building with him that day – he had 253 rounds of ammunition when he died.

Sedensky released the nearly 50-page report on Monday, saying that no charges would be filed, and that officials had assembled a comprehensive timeline of the fateful morning. Sedensky also reported that after the scrupulous investigation to find a possible motive was completed and fruitless, the reason behind the carnage would probably forever be unknown.

The investigation into Adam Lanza lasted eleven months, and included a painstakingly-thorough sweep of the 20-year-old’s bedroom at the home he shared with his mother, Nancy Lanza. Nancy had apparently been worried about her son in the weeks before the murders – Adam had not left the home in three months, and only communicated with his mother by email or text message.

The bedroom of Adam Lanza yielded a number of horrifying documents and evidence, such as the spreadsheet he kept that listed detailed accounts of mass murders that had taken place since 1891, as well as newspaper clippings. He was also reportedly captivated by the 1999 school shooting at Columbine High School in Colorado.

Other than the bizarre behaviors Lanza exhibited, police were unable to find anyone, or anything, to tie Lanza and his possible reasoning to the carnage. The most vital piece of evidence – Adam Lanza’s computer – was destroyed before he went to Sandy Hook on December 14th. Police believe he shot his mother in the head before destroying his hard drive and driving to the school.

In the timeline, investigators concluded that Lanza probably entered Sandy Hook Elementary around 9:29 a.m. by shooting eight rounds into a glass window. Once inside, the shooter fired sixteen rounds down the hall, which took the lives’ of Principal Dawn Hochsprung, and psychologist Mary Sherlach. After killing the two women, Lanza is believed to have walked to the office where he looked for anyone hiding. Finding no one, he then walked, and entered, the classroom of either Victoria Soto or Lauren Rousseau. (Police were unable to determine which room Lanza entered first, although he did eventually kill himself in Soto’s room.) In Rousseau’s classroom, Lanza shot and killed Rousseau, aide Rachel D’Avino, and fired 80 shots at the children. One child in Rousseau’s room survived by hiding behind her classmates in the bathroom.

Lanza then proceeded to the next classroom, presumably that of Victoria Soto, and fired 50 shots, killing Soto, aide Mary Anne Murphy, and 5 of the children. According to The Hartford Courant, one of the students was “found under Murphy. Nine children survived in Soto’s classroom, six after they were told by student Jesse Lewis to run when Lanza’s gun jammed. Lewis was one of the children killed.”

At 9:35:39, the first 911 call from the school was placed by the school janitor, Rick Thorne, who had been running to classrooms, locking the doors and telling children and adults to stay inside. Four minutes after placing that call, the first officers arrived on the scene, though they waited outside for two minutes before entering the building, to ensure there was not another shooter. Upon their arrival, officers reported hearing gunshots, and within six minutes, officials were inside the building. Lanza is believed to have shot himself within minutes of the first officer to arrive; he died at 9:40 a.m.

The report states that a more extensive narration of the murders will be released at a later time by the state police.

Main image courtesy ABC News via YouTube.