First of all, I work in a rural county, so what I say will likely not apply in many other jurisdictions. Where I am, police are always the first to go. Even if the ambulance arrives first, it will "stage" in the area until police go in and secure the scene. This is for the safety of the EMT's. You'd be amazed what the other people on the scene (family and/or friends) are capable of in moments of shock and grief. Once the scene is secure, the EMT's will come in, and if it's a definite DOA, they'll go ahead and call for the coroner. From my perspective, that's it until the ambulance radios in they're transporting to the morgue.
All but one of my calls were gunshots. I live in a rural red state, so it goes without saying guns are the primary mode. I had one hanging, and being in a rural place with long response times, he had long enough to CTB before first responders arrived.
Knowing what I know, if you're using a method other than gun, like hanging, gas, OD, etc. You're going to want to have some way to delay that call or txt because the job of 911/police/EMT's is to get there ASAP and "save" you. And that could mean you end up in a vegetative state or something if they're Johnny On the Spot.
When I CTB with nitrogen/Exit Bag, it's really going to throw these hicks for a loop because they'll never have seen it. I'll have to leave a detailed note explaining it.
I hope this helps. I'll be glad to answer any more questions as long as I'm here.
