Here's a list of every school shooting over the past 50 years
Over the past 50 years, there have been nearly 250 school-related shootings across the United States, a Tribune-Review analysis found.
That includes more than 130 since the 1999 incident at Colorado's Columbine High School — a massacre that left three dozen people dead or injured which often is used as a baseline in reporting school shootings.
As the Washington Post reported , a leading group that tracks school shootings and that is frequently cited counted the Valentine's Day 2018 mass shooting at a South Florida high school as the 18th such incident this year nationwide.
In reality, it was the fifth, the Washington Post said.
Everytown for Gun Safety , a nonprofit advocacy group, explained that its criteria for a school shooting is "any time a firearm discharges a live round inside a school building or on a school campus or grounds."
The group since has amended its list under a tighter set of rules.
The Tribune-Review used its own research and set of criteria for its list, which includes incidents going back 50 years to 1968. The list includes:
• Shootings that happened on or near school campuses while classes were in session.
• Shootings where students were present, such as ones on school buses or at school-sanctioned functions, such as athletic events and dances.
The Trib's list does not include suicide-only incidents or shootings that occurred on or near school campuses when classes were not in session or at times students otherwise were not present.
Shootings on college and university campuses are included in a separate list using similar criteria.