If it’s an unexpected death, EMS get called and the death determination will be made by doctors after EMS brings the patient into the hospital. If the death occurs at home and was expected, a homecare doctor (or in some areas, homecare nurses can as well) will certify the death. Only if a healthcare professional is suspicious about the death or a crime was involved will it be elevated to an medical examiner or coroner, because there are a whole lot of deaths and not many coroners.

Realistically, what this means is that sometimes we do miss homicides when they’re in people that were likely to die anyway. So unless this was a horrifically obvious murder, I don’t think Grandpa would have had to fear much from the death of a person who was of an age where everyone expected them to die of old age anyway.

And if you really want to know something horrifying, coroners are elected officials who don’t even need to have any medical training. So a homicide that isn’t obvious could easily slip past plenty of coroners. (Medical examiners do have to be doctors, though not necessarily forensic pathologists, and this is why everywhere should abolish the antiquated coroner system and switch over to having MEs instead.)