Sandy Hook Elementary School shooting
The incident is the deadliest mass shooting in Connecticut history and the deadliest at an elementary school in U.S. history. The shooting prompted renewed debate about gun control in the United States, including proposals to make the background check system universal, and for new federal and state gun legislation banning the sale and manufacture of certain types of semi-automatic firearms and magazines which can hold more than ten rounds of ammunition.
A November 2013 report issued by the Connecticut State Attorney's office stated that Lanza acted alone and planned his actions, but provided no indication of why he did so, or why he targeted the school. A report issued by the Office of the Child Advocate in November 2014 said that Lanza had Asperger's syndrome and, as a teenager, suffered from depression, anxiety, and obsessive-compulsive disorder, but concluded that these factors "neither caused nor led to his murderous acts". The report went on to say, "his severe and deteriorating internalized mental health problems[...] combined with an atypical preoccupation with violence[...] (and) access to deadly weapons[...] proved a recipe for mass murder." Provided by Wikipedia