It is being conveniently overlooked by "the media," but a few years ago the Feral .gov had a program for funding police officers in schools. They stopped doing that after the chosen one was elected, but they didn't make any announcement. Naturally, the states and local governments didn't choose to fund the programs after the "free" money from Washington dried up, so the programs were stopped.
In 2005 I was hired to review the plans for a major high school renovation/alteration/additions project. The school is laid out with a security desk and security office just inside the main entrance. When I did my review, it was my understanding this was for a police officer. Today, there is no police officer in that school, there are two older part-time "security officers" who are on duty only during the morning hours to sign visitors in. Later in the day, there is only one.
The entrance doors are all glass. They get locked after the end of school bus arrival but, as shown at Sandy Hook, like locks, glass doors are for honest people. Anyone who wants to get in can just shoot out the glass.
In the course of my review, I also noted that the existing wings had all concrete block walls in the corridors, but the new wings were planned to have glass sidelights adjacent to each classroom door. This was just a few years after Columbine and security was (supposedly) a high priority. In fact, I was briefed that the school had an emergency lock-down procedure. So I asked what the point was of locking the classroom doors if there was a glass panel right next to the doorknob that a shooter could kick or shoot out. The architect's response? "We like them. We think they add a sense of openness to the classrooms."
I have attended adult ed classes in those rooms since the addition was built. The sidelights don't add anything -- but they do make the classrooms vulnerable.
I also asked about room keys for substitutes. They don't get them. So how is a substitute teacher supposed to lock the door if he/she doesn't have a key? same thing for teachers in specialized subjects, who "float" from one classroom to another. They only have the key to their home room -- IF they have a home room.
The architects hadn't considered that, the school board hadn't thought about that -- and they continued to not think about it after I brought it up, because they didn't have answers and they didn't want to think about it.
If you look at security at any really secure installation (such an American embassy in foreign countries), security is achieved through layering of elements. There is no one thing that can defeat any and all efforts to gain entrance. The security has to be a series of obstacles, each of which must be overcome one-by-one. Even this should not be counted on to stop a determined attacker, but to delay the attack/intrusion long enough for the cavalry to arrive.
We don't secure our schools that way. Glass doors with buzzers and metal detectors operated by unarmed retirees will stop only honest people, not determined evil-doers. That's what we need to get across to our elected representatives, and to the talking heads who find it easier to blame it all on the GUNZ!