favorable environment is where yoiu have relative humidity, 50% humidity or more, humid conditoins....can get marine something... ????
Shade trees will help keep temps more stable, body in shade will decompose "slower"..if part of body is exposed to sun and another part isn't..it will be differential decomposition.
hypothetically..if the body wasn't dumped until the 13th, based on weather, rainfall etc., the body could Not?? have been dumped on the 18th...