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

I don't think there has ever been a school shooter who has attacked a school from a standoff position. I agree there is no perfect scenario... but having a means of defense is much better than the alternative.

SSgt Joseph Baptist - And I know bartenders who don't think they know everything because the General sat there drunk and running off at the mouth.

SSgt Christopher Brose - Well I'm not going to continue a long debate here, because we obviously have divergent beliefs when it comes to guns in school. I can only speak of what goes on here in my area of NY and I know and interact with many police officers and know they spend considerable time on a weapons range qualifying on their weapons on a regular basis. Bottom line is I would rather pay trained uniformed people whose main job it is to be proficient with weapons to defend our children. I believe that with the exception of uniformed armed security / police schools at least here in NY should remain gun free zones (I don't know or have a say in what other states do or don't do). You make some valid points regarding my use of terminology, and yes someone with a concealed carry permit should have there weapon on them at all times, but who is going to make sure that they do? The president in his speech said nothing about taking other measures to ensure school safety other than allowing teachers to carry, in my opinion he wants to take the cheap and easy way out (not the best way). I think it would be very hard for a police officer to tell the difference between some of the younger teachers today and an armed intruder, which is one of the big reasons I think people protecting our children should be uniformed law enforcement officers or paid uniformed security. I respect your views on the subject, but I think we will continue to disagree regardless of what we type here on this forum.

SSG Ray Elliott - It would be a lot easier to tell the difference between an armed teacher (even a young one) and a shooter than you seem to think, I have covered this at length elsewhere. Regarding your faith in New York City cops, do you not remember the case of Amadou Diallo, who the cops shot at 41 times but hit only 19 times? And he was unarmed! It's great that the cops you know go to the range a lot, but the uniform itself confers no greater ability or even greater practice habits than many civilians have. And I say all this knowing I'm not going to change your mind, but the points needed to be addressed.

SSgt Christopher Brose - I tell you one thing for sure. If I were a cop responding I would be about 1000% happier,to have some inside information prior to entering the building. Can you say amen? These known staff inside will already be known to the police. They will most definitely be in continual communication with law enforcement prior to and after their arrival. Each school will have an advance plan practiced and coordinated with local law enforcement. It's not going to be some fly by wire grabass and chaos..... that's what you end up with when you have a bunch of uncoordinated and unresponsive deputies standing around outside like drooling idiots.
"Thought the shots were from outside the buildings"
Yes, quite likely.

It is no where near as complicated as you are making it, and no one can train for every variable. That course arrives at "analysis paralysis."

The decision process.
_Gain control of those students within your zone of influence
_Have students flee or Shelter in place.
_Assume defensive firing position to cover the retreat of fleeing students or to protect their hide positions.
_Await movement of shooter into your kill zone
_When a clear unobstructed shot presents itself and you are sure the target is the assailant, commence firing.
_Upon definitively striking the target advance while firing until the target is disarmed.

At any point in the process if law enforcement enters your zone of awareness, disable your weapon and disarm yourself.

Maj John Bell - I am answering the questions asked by the op not setting up an analysis of how a specific active shooter incident in a school setting would go.

Darlene Holt - Major Bell wasn't setting up an analysis of a specific shooter incident. Just simple straightforward common sense procedures from start to finish.
Never have I seen the complete picture in simple step by step instructions laid out so cleanly. Thank you Major. Maj John Bell

I don’t think the expectation is for teachers to clear rooms, but rather be able to protect their own rooms, or protect their students as they evacuate.

Aggressive active shooter response is key to saving our youth. Armed teachers hunkered down waiting cause more deaths.

Another troubling point is The Shooter walked out with other students, or on his own. The whole sad and tragic event was a SNAFU of Buraucratic Ineffectivness.

1SG Klayton W. Hayes - When I was on Barracks duty (85-88), we trained in clearing techniques with both armed conflict military ROE and with ROE more akin to civilian law enforcement ROE. As part of my training, I and a handful of my NCO's attended Police Officer Survival Training (POST) and Hostage Rescue Team (HRT) Training hosted by the Seattle Police Department and the King County Sheriff's Department. I do not claim expert status but I feel reasonably well-informed.

After initial spool up (6-8 weeks with a total of40 hours of classroom instruction, 120 hours dry fire and live fire training and 40 hours of probationary status paired with an experience team member), we found that to maintain minimal proficiency, and to avoid intramural firefights between separate advancing on the same threat, and coordination SNAFU's required about 6-8 hours dry fire and live fire training every three week cycle. Keep in mind that our primary mission was facility security. Plus our environment was not nearly as flush with potential collateral damage targets; and we were far less likely to stand in front of the long green table explaining why we shot someone we should not have, in a real threat event.

There is no point in setting a performance standard that volunteers will find too burdensome to achieve and maintain. A half dozen volunteer teachers and faculty members whose normal classrooms or workstations are strategically placed, with identified kill zones, and restricted avenues of approach will substantially delay and complicate the tactical problem an armed assailant faces.

SSgt Joseph Baptist

Sir, I served as a Military Police Officer for over 20+ Years in the Army. I Provided and supervised General Officer protection up to the 4 Star Level. Physical Security of a Special Weapons Site where 5 member teams were trained in live fire active shooter response. Tour in Vietnam protecting a airfield that housed aircraft vital to national intelligence. After the service I was employed as a armed Security Officer at one of our Nuclear Power Stations. Individuals of all levels of experience were trained in armed response techniques. Finally I was a Federal Police Officer with the rank of Sergeant. Incidents involving armed response and the employment of weapons to counter threats can not be reviewed by knee jerk what ifs and should haves. Sir, stick to your Infantry knowledge as a rifleman and I will rely on mine as a Law Enforcement Professional. We SAFEGUARD hospitals, airports, politicians, courthouses, military installations, BLUF : Time to protect our most valuable asset, our little children, from harm with on site trained teams prepared to end the threat. Those kids are our futher.