Putrefaction: An Additional Complicating Factor in the Assessment of Freshwater Drownings in Rivers.

Background hypothesis: That bodies immersed in freshwater (rivers) may show greater changes of decomposition than bodies immersed in saltwater (sea). Fifty de-identified river drownings and 50 sea drownings were randomly selected from autopsy files at Forensic Science SA, Adelaide, Australia and assessed for decomposition.

RESULTS: The river cases consisted of 43 males and seven females (M:F 6:1); age range of 2-92 years (mean 46.8 years); decomposition-16/50 (32%); postmortem interval 1-14 days, average 3.8. The sea cases consisted of 36 males and 14 females (M:F 2.6:1); age range of 9-81 years (mean 50.7 years); decomposition-2/50 (4%) (p < 0.001%); postmortem interval 1-6 days, average 2.8. As decomposition reduces information obtained at autopsy, postmortem examination of deaths in rivers may be less informative than deaths that have occurred in the sea. The reasons for less decomposition in the sea include cooler temperatures, exposure to salt and shorter postmortem intervals.