I have a very close friend who suddenly developed a mental disorder, and before he started his therapy and medication, he did this. And then they called the cops (rightfully so), and they came and arrested him. IIRC, they got a restraining order as well. I can’t say I blame them at all. This is absolutely terrifying.
Luckily he got help and is doing awesome now. He’s back to his old self and wouldn’t hurt a fly.