> But if someone starts shooting inside while they’re at the door, their legal rights are typically restricted to apprehension.
This is simply not true. Most states that regulate armed security guards have a duty to protect. It’s part of the training they receive and licensure to be able to carry a weapon for their job as an armed security guard.
Also, in most states, a private citizen carrying a weapon can who is just a bystander is legally allowed to use lethal force to protect other people and even if that means to run into a room and dispense it.
I think what may be confusing you is that guards can’t just blast for anything (like cops can). But if there’s someone with a gun drawn (or other lethal weapons) then it’s basically open season for anyone to kill that person to eliminate that threat.
Most people won’t seek out danger if they hear gunshots or see something. But armed guards have that as their job.
If I hire a security guard who is licensed to carry a gun and they don’t intervene if some psycho is waiving a gun around then that guard is doing a bad job.
Guards with guns are very different from the mall cop type people who you see as loss prevention officers that can’t do much. But they aren’t there to protect you from harm, they are there to reduce shoplifting.