From the linked piece:
Mass school shootings are incredibly rare events. In research publishing later this year, (James Alan) Fox (Lipman Family Professor of Criminology, Law, and Public Policy at Northeastern) and doctoral student Emma Fridel found that on average, mass murders occur between 20 and 30 times per year, and about one of those incidents on average takes place at a school.Not according to the bleating gun control crowd. The actual numbers are pretty bad, but they always have to inflate them because apparently reality isn’t bad enough. It’s like hate crimes. There’s more demand than there is supply.
—
Their research also finds that shooting incidents involving students have been declining since the 1990s.
—
Four times the number of children were killed in schools in the early 1990s than today, Fox said.
“There is not an epidemic of school shootings,” he said