On December 14, 2012, a mass shooting occurred at the Sandy Hook Elementary School in Newtown, Connecticut, United States. The perpetrator, 20-year-old Adam Lanza, shot and killed 26 people. 20 of the victims were children between six and seven years old, and the other six were adult staff members. Earlier that day, before driving to the school, Lanza fatally shot his mother at their Newtown home. As first responders arrived at the school, Lanza killed himself with a gunshot to the head.

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 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 they "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."

Background

As of November 30, 2012, 456 children were enrolled in kindergarten through fourth grade at Sandy Hook Elementary School.