Over the past several decades, the presence of school-based law enforcement (SBLE) has grown steadily in the United States. In recent years, along with the steady growth of SBLE, criticisms of SBLE have grown louder and more pointed. This brief reports on the results of a study that applied a rigorous literature synthesis method--a systematic review--to synthesize the empirical literature on the relationship between SBLE and crime and behavior, perceptions of school, and learning outcomes.