http://tribes.tribe.net/emergencyservices/thread/dc747856-f163-4158-97ef-590fbb11ae86
Many drownings are actually homicides and first responders' observations and incident reports into them may be critical in initiating an investigation.
The initial determinations of the actual drowning incidents as accidents listed above are not uncommon. However, what we believe is uncommon is the discovery of their red flags and the ensuing investigations. How many other homicidal drowning cases are being missed? We believe far too many.
Responding EMS and fire personnel can make a critical difference in not only whether a law enforcement investigation is opened for a body-found-in-water incident, but also in whether a rightful conviction can be obtained provided the right steps are taken.
Our experience with thousands of law enforcement, dive team, fire and medical personnel across the world has convinced us that a large percentage of homicidal drowning incidents are either not sufficiently investigated or are not investigated at all.
There are several reasons for this and "tragic accident" is too common a mindset, one that can cause tunnel vision. The red flags normally found on homicide victims or at the crime scenes on land are rarely present, and law enforcement and medical personnel are not trained to recognize the red flags specific to homicidal drowning.
http://en.wikipedia.org/wiki/Illegal_disposal_of_bodies_in_the_water
Many criminals dispose of bodies in a river, hoping that the body is carried away. However, this method will most likely lead to a quick detection of the body, because the body gets entangled at the side of the river, or stopped at a dam, or is simply seen floating by others. A disposal in large lakes or oceans is more likely to hide the body, but a decomposing body can develop a strong positive buoyancy due to the decomposing gases being trapped underneath the skin. This may bring the body up to the surface, or at least increase the movement across the ocean floor due to wave actions. Many bodies have washed up at the shore. Bodies have also been discovered in the nets or lines of fishermen, and occasionally, bodies are also discovered by divers.
Very cold water with little oxygen may even preserve bodies, allowing for an easier identification, as for example Margaret Hogg, the Wasdale Lady in the Lake in Wast Water lake in the Wasdale area (see National Trust Properties in England). She was found after 8 years, with her body preserved like wax.
http://books.google.com/books?id=32...k_result&ct=result&resnum=6&ved=0CBYQ6AEwBTgK
(I hope that link works...there's an excerpt from a book...first few lines in the first paragraph of that page shown - Forensic Pathology Reviews, Volume 3 By Michael Tsokos page 58)
http://clintvanzandt.newsvine.com/_news/2009/03/22/2583683-the-smiley-face-killers
Some of the victims were allegedly held for an unknown period of time, possibly tortured, and then disposed of in a local body of water, thereby depriving investigators of valuable physical evidence of the crime.