When I was 17, I still lived at my moms house. We were in a middle class neighbourhood, so it wasn't necessarily a bad area for the most part.
I was taking out the garbage one night as the sun had just gone down. I walked the first garbage can out and these two men were arguing across the street. I walked back and got the second one, when I turned around, one of the men lifted a gun and shot the other in the head point-blank. The man with the gun stared directly at me, then turned and fled.

I was surprisingly calm about it until I was on the phone to the police, then suddenly I starting freaking out and panicking.

As far as I know, they never caught the guy.