In this paper we study the impact on student absenteeism of a large school-based community crime monitoring program that employed local community members to monitor and report crime on designated city blocks during students' travel to and from school. We find that the program resulted in a 0.78 percentage point reduction in the school-level absence rate (11 percent effect). We explore two potential channels to explain this: we find improvements "outside of the school walls" in the form of reduced crime near treated schools and "inside of the school walls" in the form of reduced incidents of serious student misconduct.