Barring any outward signs of strangulation as in bruising on the neck or petechiae, if a body is found in water, how is it determined the cause of death was not drowning?
To my understanding, when a person is killed before being dumped into a river/lake, water is not found in the lungs. Specifically, I’m wondering if water can be taken in through the mouth, into the lungs and finally into the alveoli through the body’s movements with the natural currents of the water. Would air already present in the lungs create a positive pressure, prohibiting this from happening?
Just so you know: I’m curious about this from reading one of the GD threads on the Peterson trial, in which the cause of death is said to be unknown. I’m left thinking, “What do you mean it’s unknown? Couldn’t the pathologist tell?”
Underwater investigations and water related death analysis are not topics that can easily be summarized in a single post - my own training on the subject entailed several weeks of study. That said, in most drownings the lungs are indeed filled with water. In those that are not, this is typically the result of laryngospasm - cold water entering the trachea triggers a reflex which closes the epiglottis preventing further water ingress. If the body is then retrieved prior to the relaxation of this reflex (after rigor mortis has subsided), only minimal amounts of water may be found in the lungs.
Incidentally, the best reference available on the subject (short of forensic pathology texts) is “Encyclopedia of Underwater Investigations” by Cpl. Robert G. Teather, RCMP. Bob unfortunately passed away recently after a long battle with diabetes, but his work has become a de facto standard as training material for dive teams that deal with this sort of thing.