Real solutions mostly depend on the federal government getting out of the way except to assist or grant some funding, but not all. GC has it right, there is plenty of money in Washington already, redirect it.
The parents of the kids in the school, through their school board, should decide the security measures to be taken at their school. If the feds want to have grants available to help offset costs of hiring security guards, or putting in metal detectors, bulletproofing some areas, etc, then it's something to consider.
One size does not fit all. How many times do we cuss the federal government, from both sides of the aisle for their incompetence? For favoring one group over another? That's why the logical solution is for the federal government is to get smaller, not larger, and allow states and local authorities to decide most issues themselves. How much more money would local communities have if federal government was smaller, and didn't need to waste a trillion dollars every year?