Indiana/Shooting/Firearm Question

Depends on the state. In Missouri, with a permit all they can do is ask you to leave. With Constitutional Carry, no permit, you could be arrested.

I hope I’m not continuing a hijack to address two things here. First, this was not even close to a random attack.

The sheriff’s office did not give a motive for the attack, but said that Mr. Madden had previously been in a relationship with Christina Siau, and that he had unspecified “mental health issues.”
https://www.nytimes.com/2022/07/20/us/montana-shooting-attack.html

Also, where did you see this?

The articles I’ve seen all say she “fought for her life and killed the attacker” without specifying how she managed to do that.

Derick Amos Madden’s sister told The Daily Beast that the unthinkable attack near Glacier National Park only ended when he was killed with his own knife.

Derick Amos Madden, Ex Who Unleashed Terror on Siau Family in East Glacier, Montana, Had ‘Red Flags’ (thedailybeast.com)

Thank you. I figured if she had used a concealed firearm that would have been mentioned in most of the stories.

I didn’t read the article, I don’t subscribe to the NYT
I would like to know what the good guy did after he shot the bad guy. Did he conceal or lose his firearm before the cops showed up?

Well, well, well

So if you can’t stop the lunatics, the next best thing is to give people the means to defend themselves

In which of those would armed bystanders have been able to do much, if at all.
Maybe the knife attacks.