How do Forensic Scientists Collect Evidence from Water


Forensic science has significantly helped with the solving of many crimes. One of the most productive ways this is done is to collect and analyze various types of evidence. 

Many are not aware that water is one of such kind of evidence that forensic pathologists make use of. If a corpse is located in a freshwater body, these experts can deduce the time when the person died. The temperature of the organs in the body can also serve as guides during these forensic investigations. The following parts will explain in detail how forensic scientists get evidence from water. 

Ascertaining the Period of Death

It becomes increasingly hard to determine with accuracy the period of death with time. Temperature cannot be used as a reliable indication if weeks had passed before the corpse was discovered. Forensic entomology is relevant here as maggots found in the corpse can assist the experts in calculating death’s timing. Pollen is another indicator that the researchers use when trying to ascertain the period of demise accurately. 

Extraction from Seawater 

The investigation commences immediately after that body is extracted from the water body. This is because the body would have been influenced by several factors like salt content, pH and temperature. All these factors can complicate knowing the precise timing of death. There are cases where some even think that it is impossible to deduce the time of death for a corpse retrieved from a body of seawater. 

Forensic entomology is very helpful for the body taken from the land surface and is seldomly utilized for corpses taken from the water. This is mainly because the corpse would have to experience some floatation on the water’s surface, which happens only rarely. 

Trauma that the body experienced from being in the seawater also complicates the matter. It makes it difficult to distinguish from the trauma that was inflicted in a criminal scenario. 

Forensic Science in the Waters

The good news is that latest advances in science are allowing scientists to overcome these challenges. The newest discoveries are making it possible for the researchers to have a deeper understanding of corpses that have been evacuated from water. One of the studies that scientists carried out in this regard involved getting a freshly-killed hog, the corpse was measured and it was dropped on the ocean floor. 

An underwater camera was put in place to record the stages of decomposition of the corpse. The scientists took the time to assess the water temperature, the level of salt in the water body and other parameters. The results that they obtained were quite informative, and they demonstrated all kinds of changes. Scientists also observed the pattern of sea organisms like the crustaceans. It was also noticed how the other creatures fed on the corpse. 

Decomposition of Corpse

Observations of corpses on land showed that decomposition starts from the head, and that is where the initial concentration of maggots is located. The interesting thing here is that this observation is seen only on corpses found on land, and it is a different thing with corpses found in the water bodies. 

The head is the last component to decompose if the corpse is found in a water body. The hog was killed via a bullet to the head. While some may think that the head with the bullet wound will be the first to be decomposed, the head was the last part to rot. 

This is a fascinating discovery in the field of forensic science. The interpretation is that when the body is located inside a body of water, all wounds that happened on the face – with the body undisturbed – are usually a result of criminal activity. 

The research assisted the scientists in gaining more insight into the decomposition of bodies in the water bodies. This was used in extrapolating the period of death for the animal or even human beings. 

Another factor that helped shed more light is that the corpse remains on the ocean floor for a considerable time before it floated to the surface of the water. The corpse floated to the surface of the water due to the gases produced during the stages of decay. The corpse has a bloated appearance because of these gases. 

Recent Advancements

Forensic scientists have also discovered that the head alongside the upper and lower limbs will be detached from the torso during the decomposition of a corpse in the ocean or similar water body. In many instances, these parts do not come to the surface even though some feet have been discovered before on Canada’s shoreline. 

Forensic Science in the Oceans

The study also gave more information regarding the marks that other sea creatures have left on the carcass. This allowed the scientists to have an accurate idea of the predator that attacked the corpse or if the death resulted from some criminal activity. The summary is that the latest advances helped comprehend the interaction between corpse, criminal activity, and water bodies like the oceans and seas. 

Solving Crimes Using Microscopic Algae in Water – Forensic Science in Action

One of the most sophisticated advancements in this niche is that scientists have solved crimes using the microscopic algae that they scooped from water bodies like murky rivers. This is possible because a criminal leaves traces of evidence behind in the environment. This principle has been known since the 19th century, but it has been exploited fully only recently. 

The microscopic algae are referred to as diatoms, and they are present in any water body. Diatoms are present in seas, oceans, lakes, local water supplies or even wet surfaces of rocks. Diatoms have been used in drowning cases but of recent, they have been utilized in other aspects of investigations in forensic science. 

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