Do they?

Let's attempt a hypothetical analysis of such a situation. 

OS starts shooting into a crowd of people (bystanders). Said bystanders would react with confusion at first (with some possibly realizing what is happening at the start) which then switches to fear/panic as they try to figure out ways to survive. Perhaps one of the bystanders is able to start calling 911, and said bystander would likely not respond with "Help! Someone started shooting people at X! The shooter is wearing Y clothing, is using Z weapon, and appears to be of A race". Instead, the bystander would likely respond with "Help! Someone is killing people at X location" before returning to trying to stay alive. The 911 operators would scramble to send in any nearby police, as well as alerting all other units of the situation. When the police arrive (if the shooting is still taking place) the information they are most likely going to have is that there is one (or more) active shooters at the location.

Now let's add a bystander shooter into this mix. Say a bystander just happened to have a concealed gun on his person, and instead of panicking like everyone else (which is unlikely, the flight/fight scenario does seem to have a sort of group think involved. Which of course sort of makes sense since if a group of people are running away from something it would probably increase your own survival by running as well) this lone bystander decides to attempt to save the day with his gun! This bystander then attempts to take careful aim (which is unlikely as there would still be people in full flight running into the line of fire, and also assuming our valiant bystander's brain still isn't in flight mode as well) before ideally taking out the shooter without any collateral damage (which is also unlikely). 

Returning to our fleeing bystanders, the 911 call would likely involve "There is a shooting at X location, and there were two gunmen". If they were lucky they will also be able to inform the dispatchers that the second gunman was trying to take out the OS, but that's likely going to be a detail that is left out. The police arrive on the scene (ideally after the OS has been dealt with), but then they're left with the question of who ended up shooting who? Has the OS actually been dealt with? Is the BS actually involved with the OS, was there a plan between them that allowed one to escape to continue shooting?

If the BS wasn't able to take out the OS causing a minor gun battle what would be the police response? They would shoot both of them and ask questions later. Which of course would open the department up to any number of lawsuits from the BS family, which would be something the police would want to avoid.

In an ideal scenario the only bystanders killed were done by the OS, but if the BS happened to cause any collateral damage what would be done to them? Would the BS be charged with murder? Would the BS face any civil suits from the families of those he may have wounded/killed? 

If there was going to be a bystander shooter, the only type of person I would trust to be able to actually handle the situation would be an individual that was in the military (ideally one from active duty for more experience in said situations) because if not I fear for the consequences of the random Joe that thinks he'll suddenly turn into Rambo in such a situation. 

As for prison reforms, I wholeheartedly agree. Sadly, I think I'm far too cynical to ever think that they'll ever occur.

If only. 

A professional can defend against a longsword or a katana with a fork!

A gun, the power to take life, is immensely empowering. People hate it when you threaten their power.

*Maybe if you're a child. Or retarded. Again, they are simple machines, that come with a simple set of safety rules. Driving a car with a manual transmission is literally more complicated than using a firearm.

And whether or not I would be able to stop a shooting asshole, well, I can't say for sure. Nobody can. Either way, I still fail to see how having the ability to return fire is worse than laying down in the fetal position and accepting your fate as a shooter approaches. Seriously, what sense does that make? As if an attempt to defend yourself is some Rambo fantasy, or something.

The whole point of CCW is not to be the police. It is for defensive, not offensive purposes. To say that you'd better off defending an area empty handed, or with a pencil, or something, is just silly.

I'll be sure if, god forbid, I'm ever in that situation, I'll just toss my gun aside and just wait until it's my turn.

A well armed society is a polite society.

I can do the same with a crowbar, what was your point, if you had one?

Hmm? To quote myself "The idea that gun carriers are always (or even half the time)going to react calmly, professionally, and with perfect ability in the case of active shooter situations is nonsense."

10 Cases, 10. Versus the tens of thousands of murders and injuries that result each year from clowns with guns.

Again, all for gun ownership. I've posted pics of various firearms laying around my house on these very forums. You wanna conceal carry, or open carry? Go ahead! More power to you. Wanna bring your gun to the barbecue down the street to show your buddy that sweet new piece you got? Awesome, sounds like fun. But lets not pretend guns are solving more problems then they are creating, and let's not walk around acting like we are gonna stop mass shooters in the off chance we are armed, in the area, and react with perfect clarity and precision to the situation.

Gun violence is gonna happen, gun control or no. Its the world we live in. But I'm not willing to play pretend and ignore the sheer numbers here.

No support for gun control, because that would threaten gun owners' power.

The power to defend themselves, you mean.