The number of school shootings in the US in the year 2020 was 10 incidents that resulted in injuries or deaths at K-12 schools. This is based on data tracking firearm-related injuries or fatalities on school property for that year. More broadly, school shootings in recent years have ranged higher, with, for example, 51 such shootings in 2022 and 39 in 2024, indicating an upward trend overall.

If more detailed yearly breakdowns or definitions of school shootings are needed, please let me know!