How do doctors know if someone died by drowning or died before being drowned?
For bodies that are still ‘new’, it can be seen from their appearance. If the color around the lips or nails turns blue, it’s a sign of death from hypoxia (lack of oxygen). If not, then there is a possibility of being killed before being drowned.
Second, blue nails and lips are indeed a sign of hypoxia, but there is still the possibility that the victim was killed by ‘cutting off’ access to oxygen, then drowning. So, there are 2 things to look for: signs of violence (eg: strangulation) and foam. There are no signs of violence but if no foam is found, then this will be a big question mark.
Foam is an important indicator because it is a chemical-mechanical reaction between mucous membrane fluid (mucus), water, and… attempts to struggle (when drowning). Usually, foam comes out of the nose and/or mouth. Yes, this is a visual indication, without surgery/autopsy.
It can also be ascertained from blood chemistry, such as alcohol levels. Although not a guarantee, the high alcohol content, logically indicates (confirms the allegation) that the victim fell and died, rather than being killed.
If through an autopsy, it’s just a matter of seeing the condition of the lungs, whether they are filled with water or not. If it is filled with water, it will die by drowning. If the lungs are dry (yes, the lungs are never dry, but you know what ) then he dies before drowning. If it’s still not working, just try checking the condition of the fluid/microbes in the lung fluid and in the pond/lake where the body was found. If the body is found in a lake that is clearly full of algae, protozoa, etc. where for example there are many dinoflagellates such as Peridiniumbut in the lung fluid no such protozoa were found; Instead, the findings are high levels of hypochlorite (a hallmark of swimming pool water), now this actually makes a question mark. His death was indeed due to drowning, but… how come… something went wrong??