The Federal government reported 235 school related shootings. NPR could not confirm 224 of them.
The rest of the article goes on to explain the discrepancy-
The biggest discrepancy in sheer numbers was the 37 incidents listed in the CRDC for the Cleveland Metropolitan School District. Roseann Canfora, the district’s chief communications officer, told us that, in fact, 37 schools reported “possession of a knife or a firearm,” which is the previous question on the form.
The number 37, then, was apparently entered on the wrong line.
Similarly, the CRDC lists four shootings among the 16 schools of the Santa Monica-Malibu Unified School District in California. Gail Pinsker, spokeswoman for the district, says that “going back 20-plus years,” no one can remember any incident involving a firearm. Their best guess, she says, is that there was some kind of mistake in coding, where an incident involving something like a pair of scissors (California Education Code 48915[c]), for example, got inflated into one involving a firearm (48915[c]).
Theres alot more to it, good article – www.npr.org/sections/ed/2018/08/27/640323347/the-school-shootings-that-werent