There's a long Wikipedia article about it that's interesting: https://en.wikipedia.org/wiki/Active_shooter https://en.wikipedia.org/wiki/Active_shooter But bas

There's a long Wikipedia article about it that's interesting: https://en.wikipedia.org/wiki/Active_shooter https://en.wikipedia.org/wiki/Active_shooter But basically, it's a law enforcement term for someone looking to randomly kill as many people as possible, without a specific victim. So, no need for hysterics – it's just a police term.