This research provides a unique seven-year trend analysis indicating that, while California has seen a decline in the use of suspensions in schools prior to the pandemic, the pace of the decline has slowed and large racial disparities in suspension rates remain. The research supports renewed advocacy efforts to eliminate schools' use of security officers to enforce school rules, finding that high schools with higher security staff-to-student ratios tend to also have higher rates of lost instruction due to suspensions, especially for Black students. [For the executive summary, see ED607058.]