Between December of 2022 and March of 2023 multiple states have had their largest school districts receive active shooter calls shutting down the school.
California 2023-02-07 Multiple SoCal schools receiving false reports of shootings
https://archive.ph/2qJnK
Colorado 2023-02-22 11 Colorado School Districts Enter Lockdowns Over Active Shooter Reports—But FBI Says No ‘Credible Threat’
https://archive.ph/C572K
Colorado 2023-02-22 More than a dozen schools across Colorado receive unfounded threats
https://archive.ph/JifWW
Colorado 2023-02-22 Updated: More than a dozen schools across the state were targeted with fake threats as law enforcement swarmed
https://archive.ph/ffoAq
Deleware 2023-03-02 Schools across Deleware, elsewhere nationwide report hoax shooting threats Thursday
https://archive.ph/YRxtG
Idaho 2023-02-22 Hoax calls about active shooter put multiple Idaho schools into lockdown Wednesday
https://archive.ph/6LCHf
Idaho 2023-02-22 Idaho high schools placed on lockdown; officials say threats are a 'hoax'
https://archive.ph/KghjY
Kansas 2023-03-01 False school-shooting calls made to more than 10 Kansas districts
https://archive.ph/3NSVT
Kansas 2023-03-01 Multiple schools across Kansas receive fake shooting calls
https://archive.ph/XxURJ
Kansas 2023-03-01 Police respond to several false calls of active shooters at Kansas high schools
https://archive.ph/DP3Y5
Michigan 2023-02-08 State, federal agents investigating whether school threats across Michigan were coordinated
https://archive.ph/sNZJr
Nebraska 2023-03-02 LPS, OPS and other districts receive hoax emergency calls; Omaha South was briefly on lockdown
https://archive.ph/l6ONi
New Hampshire 2022-12-09 State, federal officials work to find whoever was behind fake active-shooter threats at New Hampshire schools
https://archive.ph/mx1Fh
North Dakota 2023-03-02 Police investigating hoax active shooter threats at several schools
https://archive.ph/YRxtG
Oklahoma 2022-12-08 Police respond to false calls regarding threats at multiple Oklahoma schools
https://archive.ph/QlZ7p
Vermont 2023-02-08 Police investigating hoax reports of school shootings across Vermont
https://archive.ph/9a43c
National Public Radio 2022-10-24 Those fake active shooter calls to schools? A similar thing happened before NPR has found local reports indicating 182 schools in 28 states received false calls about threats between Sept. 13 and Oct. 21. These have prompted a response known as "swatting," where law enforcement swarms a location where a crime is reportedly in progress. Swatting incidents can be particularly dangerous, as officers often enter with force, guns drawn.
https://archive.ph/9rGFS
Thoughts? Additions?