If someone was shot the damage is done me calling won't help them.

We had an incident one morning where a passerby called in someone laying on the sidewalk, appeared to be unconscious. Cops and EMS got out there, and it was a shooting victim, obviously deceased, had been there for hours.

Turns out that multiple people in the area had heard shots overnight but decided not to call.

I dont know the details about exactly what kind of injuries the victim sustained, they could have died instantly, or they might not have and if someone had called in the gunshots they might have been found and taken to a hospital and possibly could still be alive today.

I'll have to talk to a cop for no reason

Department policies and how individual officers use their discretion will of course vary, but in general unless they get out there and find actual evidence that something happened, most of the time they aren't going to give a shit about talking to you. They go out, drive around the area, maybe park and walk around a bit on foot, if anyone happens to be outside they'll ask if they heard anything, and unless you indicated that you want to speak with the cops, they'll be on their way.

Also, if you call from a cell phone, we usually don't automatically get your name or address (there's some exceptions with some types of WiFi calling, femtocells, and how much emergency info you've filled out on your phone, or if you've previously called and gave your info we can look that up,) just a location based on cell tower triangulation that isn't always super accurate. Yes, we can probably get the info from your phone company if needed, but unless they actually find an issue and need to follow up with you, no one involved on our end wants to go through that process.

Just give your nearest intersection, say what you heard, say you want to remain anonymous, and decline to provide your address. If you're really paranoid about it, if your phone has a physical sim card take it out, or call from an old phone without active service and we won't even get your phone number to look up. Just please for my sake don't be a dick about it, so many of my anonymous callers get really argumentative "well why do you need my name? Nah, I'm not giving that to you, you see this is why people don't call 911, why are you asking all these questions what if I was dying I could be dead" my dude, I get it, let me just move on to the next thing already so I can hang up and answer my next call (or you can just hang up at any time, that's also an option)