The NRA and many gun fetishists cannot bring themselves to accept any accountability for gun violence and mass murder. Their position is that having more guns in our schools is the solution. It is not. It is not a practical solution at all, but exists rather as a fantasy in the minds of the gun fetishists.
There are around 100,000 schools in the USA that need to be armed. The cost per school is estimated at $85,000 a year, for one armed policeman. (I expect the right-wing will claim that taxpayers would be better off paying a private contractor, or more accurately, having the communities enrich private contractors to do this work. In this case the price per school would increase to, say, $100,000 per school.)
The price tag comes to $8.5 Billion a year. We can pay for that with taxes on guns and ammunition. Tax every bullet, tax all guns and bullets not only to cover the cost of arming our schools, but to offset other costs which come from gun violence. Make the taxes a penalty, like taxes on cigarettes or booze: guns are destructive to society, and a vice for those afflicted with the fetish, and ought to be taxed accordingly. Let's make it clear that this cost will not be paid by hurting the sick, old, and needy in America.
More gun deaths will occur in our schools, whether they are armed or not. That is 100% upon the gun lobby and the gun fetishists in the USA. They will, when more people die, disavow any responsibility, of course. And the cycle will repeat.
The USA is a sick nation.