School shootings have been a constant looming threat for students across the US, with the number of shootings on campuses dramatically increasing in recent years. In response, schools have instituted preparedness and response measures, including school-shooter drills. This essay examines the relationship between active-shooter drills and two school accountability outcomes: attendance rates and proficiency rates on statewide end-of-year tests. There are two main results. First, in English and math, students in grades three through five who test on the school days immediately after an active-shooter drill have lower proficiency rates than their counterparts who test on the days and weeks before the drill. But proficiency rates return to typical levels as tests are administered in the weeks following the week of the drill. Second, attendance rates are slightly lower during quarters when active-shooter drills occur, relative to quarters without these drills.