Mandate security at every entrance in schools

At the entrance of every school there should be a metal detector that everyone (staff, students, and visitors) must pass through. In addition, people entering the school should have to pass through a secondary, manned check-in station in which they show ID. This should be the only way into and out of a school. Schools should also increase security for open areas such as playgrounds and sports fields, so that only people that have passed through the security checkpoint should have access to those areas.