Regardless of new laws Congress might enact to help curb gun violence, school districts should take reasonable measures to prevent shootings at their schools. Many school districts face potential civil liability for the wrongful deaths of students or school personnel resulting from criminal acts that are reasonably foreseeable.
The first (and most logical) defense is to prevent potential assailants from entering school premises. Therefore, schools should follow the example seen in courthouses and other facilities throughout the country: reduce the number of entrances to the premises, install a metal detector at the entrance, and have a guard monitor the entrance at all times.
After all, even in our own homes, the first line of defense is to lock our doors and windows.