I believe law-abiding, background checked individuals should be allowed to carry guns.
But I'm seeing a lot of people post this concealed-carry thing which sounds like a John Wayne movie tagline. If you carry a weapon, according to the FBI, you are more likely to be shot or injured by a gun. The FBI also reported on 160 mass shootings and found that 3 were stopped by civilian gun force (2 by former military/law enforcement civilians) and 20 were stopped by civilians with no gun - and just under half of these situations occurred in "gun free zones".
But if statistics are "biased" to you, think of this. Have you ever fired a gun while you were moving, at a moving target, in a confined space - while other people were near by? Have you ever fired a gun in a hostile situation where you had to discreetly access your gun in a location with poor lighting? Next time you are in a movie theater, try to take out your keys during the movie, run across the room, jump behind a chair and throw your keys at someone 20 feet away - because firing a gun in a shooting situation would be a lot tougher than that.
I've seen state police training for active shooter situations. It's intense; it looked like something out of a movie - and they do a lot of this training. I'm sure military training is just as intense. But if you haven't had this training, I hate to tell you, but if a maniacal madman with no regard for life (including his own) is actively shooting, you having a gun is probably giving you a better chance of getting shot than of shooting the killer.