HumbertTetere

Not just drowning victims. Many freshly dead persons will have Dihydrogen Monoxide in their system, including but not limited to their lungs. They try to keep it a secret. Doctors will usually not write it down outside of the mentioned drowning.

If the body decays, that's a strong sign the person had the substance inside it at the time of death.

I'm sure there's some obscure source saying something like that, but at least in the bible angel feedback is no part of the creation.