Policies and what resources are available are going to vary a bit from one agency to another, but assuming it came in to us on a 911 line

From landlines, we get an address for the phone number. There’s a couple exceptions to that with certain kinds of business and VoIP lines where the address we get may not actually be the actual address where the person is, or there’s always the chance that the phone company has wrong info, but generally speaking if you call from a landline we know where you are.

From cell phones, things get a bit fuzzier. For the most part we’re relying on triangulation from cell towers to locate you (we call it “Phase II”) which means the quality of that location can vary from pretty good to basically useless based on how many towers your phone can reach, signal strength, geography, etc.

What that location looks like is we get a set of coordinates

An “uncertainty radius” or “confidence factor” which is a distance in meters from that point that the caller is probably within

A “confidence percentage” which is how confident the system is in that location (I’ve literally never seen this be anything other than 90%)

So what it ends up looking like is something like “90% confident that the caller is with 200m of 40.12345°N,-90.12345°W” (random-ish coordinates, not sure where that location actually is, but it’s definitely not where I work)

I’ve seen the confidence factor be in the single digits, and I’ve seen it in the thousands. Sometimes it takes a minute before we get a good fix, sometimes it comes in right away, sometimes we never get a good location from it.

My agency’s policy is that if we have a confidence factor of 300 or less, we can enter the call as normal with just that phase II if we’re unable to verify that location any further

And if they’re in somewhere like a wide open field or parking lot or something, 300m is pretty good, they’ll probably see you when they get out there. If you’re in a denser neighborhood with apartment complexes and a bunch of houses, wooded areas, etc. that’s really not much to go on. Usually we can get at least that 300m, but again not always.

That phase II location also takes a while to update, if we’re lucky we can only get an updated location every 20 seconds or so, so if, hypothetically, you’re in a car flying along the highway at 70mph, you could be about a half mile away from where you were by the time we got a new ping.

So we always try to verify the location, and we can’t, as my callers like to put it “just GPS your phone”

New technology is rolling out, we can sometimes get actual GPS locations from your phone which is usually more accurate and updates faster, but it depends on what settings you have enabled, what your carrier supports, etc. I think my center currently can only get it from iPhones. Same for your emergency information like contacts, medical info, etc if you’ve filled that out.

Once you hang up with us, that’s usually pretty much it, we’re not getting any further updates on your location even if we call you back and you answer.

We also don’t get any of that if you call on a 10-digit non-emergency line, usually we get your phone number and maybe a name on the caller ID, but depending on how the call got routed to us, like if you were forwarded from a station, we may not even get that much.

If we get a call with no other usable location info, if it came from a landline we can look up the phone number to get the address.

We can also look up the phone number to see if we had any prior calls from that number that we might be able to get an address from. We only store those records for about a year, sometimes our police departments have records that go further back they can look up, but we need something to go on to pass it along to the correct department that would have those records.

Pretty much anything beyond that is usually something that needs to be initiated from the police. There are only very narrow circumstances where we’re able to request for a phone company to try to ping your phone, and even if we can do it, the location may not be any better. They can also try to get subscriber info from the company to get your home address (although that’s not always super useful, people move and don’t update their address, are on someone else’s plan, etc) if they get a name and date of birth they can try to look up your info from your drivers license info (again assuming it’s up to date) property records, etc.

So if we get a call that’s just an open line with heavy breathing or something else suspicious, we’re using those tools to try to get someone out to at least the general area to try to locate the, and police are hopefully using whatever other resources they have on top of what we do to try to narrow it down if needed.

We’re probably going to enter it as a hang-up call or a suspicious activity which just gets a police response unless we heard something that makes us specifically think fire or EMS are needed.

If we heard yelling, gunshots, alarms going off, etc. then we might enter it as something else as appropriate to make sure we’re sending the right resources.

If they stop talking to us while we’re on the call, hopefully the first thing we got from them was a location, it’s the first thing we ask, otherwise all the same thing applies.

If it’s just an open line, we’ll stay on for about 30 seconds or so to see if we hear anything. If we don’t we enter it as a hang up, try to call it back, and if they don’t pick up we just kind of move on and it’s in the hands of the police to do something about it.