Interactive: School shootings since Newtown, Dec. 14, 2012

Incidents were classified as school shootings when a firearm was discharged inside a school building or on campus, as documented in news accounts. Incidents in which guns were brought into schools but not fired, or were fired off school grounds after having been possessed in schools, were not included.

Key:

Elementary

Middle

High school

College

Sources: Everytown for gun safety, Times reporting