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

In every case (so far) of a school shooting, the shooter was not a well trained individual but was a "troubled" young man who may have had an initial target in mind but then turned on the mass. The Dallas shooting on the other hand was by a well trained, ex-mil rifleman who intentionally made himself a hard target.

So, is it realistic to believe a teacher could defend against an active shooter? Yes, IF the teacher has had minimal firearms training and IF the teacher isn't trying to be a hero.

Ever been shot at? when lead starts coming you way, even if not extremely close you focus on that- not shooting innocents and the fruitcake in FL was not bent on suicide.

"...Is that realistic?" nope.

Yes, it's very realistic. Even if you miss the shooter, you're potentially distracting him from shooting at students and giving them time to get away. And we already know teachers have died placing their bodies between the student and shooters. If teachers are courageous enough to do that, I see no valid reason not to give them the means to protect themselves and take the shooter out. A gun in the hand with no training when lives are on the line is still better than no gun at all.

More realistic than doing so without any gun. But sure, I agree. Give teachers AR-15s instead.

The real scenario should be what are the risks to an armed teacher when law enforcement enter a school in an active shooter situation with little intel. I wouldn't want to be spotted holding on to a firearm in a crowded building with officers' adrenalin flowing.

Depends on the size of the hand gun, me I wouldn't have anything smaller than a .44. Might have to shot through the door.

The suspect in the Dallas shooting was a Army Reserve Veteran of Afghanistan and even though he had rifle training he was being very selective with his targets (only shooting at Police) and in my view was not all that great with his aim. He was in a 3rd floor elevated position (parking garage) surrounded by concrete for protection from return fire.......almost an elevated bunker. Because of the echo when he fired it took Police a while to determine where he was located. Another point, a number of the BLM marchers had various assault rifles on them but didn't use them to suppress the shooter, they quickly handed their weapons over to Police because they were afraid the would turn on them as potential suspects.

Also, the Dallas Shooter was discharged from the USAR due to mental issues. Something about stealing his ex-girlfriends underwear in Afghanistan and hiding it. His former girlfriend reported him and he was on the next flight out of there it read like. USAR never reported to local police or even to his Parents they discharged him for mental reasons. He was living with his Parents at the time of the shooting and they were surprised to hear about events in Afghanistan for the first time from the press.

Texas Governor was on FOX News today and stated a lot of school districts in the state of Texas already allow teachers to be armed under the concealed carry law. So he stated it was nothing new for some Texas school districts. He stated not all Texas school districts allow it though. He said it has been allowed for several years so far.

Trigger to trigger, probably not. What an armed player (teachers, in this case) would provide in a potential active shooter scenario is a deterrent. All of these recent mass shootings happened in areas that were assumed to be gun-free zones. The shooter was not expecting anyone in the schools or the churches to be armed, and none of them wanted a shootout, only targets. If any of those cowards thought they would encounter return fire, none of them would have done it.

Yes