Is it realistic to believe that a teacher could effectively defend against an active shooter, using an AR-15, armed with only a handgun?

A teacher armed with a handgun against an AR-15 has a lot better chance of defending students than ten teachers armed with crying towels

LCpl Timothy McCain,
After the recent Florida Parkland High School Active Shooter incident that killed 17, the Columbia County School District here outside Fort Gordon, GA. changed its policy on how teachers and students should react to an active shooter (more fight or flight, versus cower and hide) as well as the more stunning change; adding one armed teacher to each school in addition to the resource/sheriff officer. Now, granted each teacher will need to be trained and certified, but the goal here is not necessarily to take on an adversary armed with only a Glock GEN4 or something similar, but to act as a deterrent, because the shooter will not know, nor will the students know and even some teachers will not know who it is. In this instance I think it is definitely a plus. We already do this at all of the local churches. No one knows whom it is, but a Deacon, Elder, or other member is always designated and armed, whenever the church is open for a mass event. We started doing this not long after the Charleston, SC Church shooting. It in my humble pinion acts as s pretty strong deterrent.

I don't think that arming the teachers is the thing to do. It will become more dangerous and out of control. Although for me I will take something over nothing. I might get lucky.

I'm not so much concerned with training ninja teachers. I am aware that it takes LOTS of training, frequently, to remain proficient enough to move towards and eliminate a bad guy. I also don't want another bloated federal agency to half-ass train armed security at schools. What I'd like to see is the lifting of the gun free zones. Just let citizens do what they can do everywhere else. Give them a chance. If a teacher has a concealed carry license, let them carry. Obviously with the understanding that A) it won't stop everything, B) there may be some complications, and C) It is a fast, simple semi-solution that requires no further tax dollars being spent. Standing by for return fire...

Whether or not a teacher could neutralize an active shooter is dependent on too many things for a simple answer. One thing I can think of as a deterrent is that if the shooter is similarly inexperienced he may be put off by rounds coming back in his direction. An armed response doesn't necessarily require a hard kill to be effective, a soft or mission kill saves lives too. Beyond that, it's too damn complicated for a simple yes or no answer.

I guess it is just as unrealistic to think that a teacher could effectively defend against an active shooter, using an AR-15, armed with nothing. Two of them tried that in Florida and they are dead.
Hunting aiin't so fun when the rabbit has a gun

If someone is firing back, the shooter may well leave the area. I think this is better than no one returning fire.

Let me give you the following option which will make this eminently clear.
You are forced to fight a violent man armed with an AR -15. Do you want to do so empty handed armed with a “gun free zone sign” or face him armed with a handgun? Pretty simple decision , right ?

It is realistIc to believe that a potential shooter would find a softer target if they realized there was the potential for multiple armed defenders onsite.

Do you trust someone from personnel or finance to do it?