Is this because you don't count gang violence as "school shooting"?
Definitions Matter
Narrow definitions (common in media/discussions of "school shootings"): Rampage-style attacks by (often current/former) students targeting the school community, frequently with multiple victims, ideological grievances, or random selection. These are rarer and overwhelmingly by White males (e.g., Columbine, Sandy Hook, Parkland, Uvalde).
Broad definitions (e.g., Everytown, American School Shooting Study/TASSS, GAO reports): Any incident with gunfire on K-12 school grounds, including disputes, fights, gang-related, accidental discharges, or non-student perpetrators. These are far more common, especially in urban/high-minority schools, and show higher Black perpetrator rates.