FORENSIC TEAMS CATCHING CRIMINALS DUE TO RESEARCH ON MICROSCOPIC ALGAE

"To Catch A Criminal"

MIGNON DUNBAR | FORENSIC SCIENTIST

H i g h l i g h t s

MICROSCOPIC ALGAE CSI OVER DRIVE LOST & FOUND

Explaining the use of algae in relation to crime investigations in solvingcriminal cases.

OverviewFrom fictional shows like CSI Miami to real life crime scenes, we

have all seen the process it takes to gather forensic evidence.

Whether it be from derelict fields, dark alleyways, or deep sea,

oceans, many environments can leave behind physical evidence of

a criminal and victim that crime scene investigators both real and

fictional can use to identify and catch the culprit.

However, this can be difficult when trying to find the best pieces of

evidence to use, and detect after analyzing and putting criminal

information together.

Discovering the use of Diatoms in Forensic Science Research

According to research microscopic algae, likediatoms for example, can be picked up fromanywhere that there is water. This includes rivers,lakes, oceans and moisturized soils. Some domesticwater supplies and even moist surfaces such asexposed rocks and sediment can harvest diatoms.

While many diatoms traditionally have been usedto diagnose deaths caused by drowning, researchhas now shown that the use of diatoms and theiruse as traces of evidence in a range of forensicexaminations has been useful throughout the fieldof forensic science.

Most forensic investigations are carried out on dry land, but according to the UnitesStates Geological Survey (USGS), nearly 71% of the Earth’s surface is covered in water.Freshwater or marine environments, for example are often encountered as crime scene

locations or sites of accidental suicide death or natural disasters. When a crime iscarried out on dry land, water may be then used by a criminal to dispose of

incriminating evidence

The use of Diatoms in Forensic Science Research

CSI OVERDRIVE

Microscopic algae like diatoms are extremely useful whendiagnosing drowning as a cause of death. Their microscopic sizeand inhabitants in flowing water means they are often inhaledand swallowed during drowning. Diatoms are then transportedthroughout the circulatory system of the body, and deposited invarious organs, including the brain, lung, and bone marrow.They can be observed under a microscope as well as compared tothe diatoms in the water where the body was found.

If diatoms are not present in the body during an examination, itmay mean that the victim did not die by drowning, but instead ifthe diatoms in the organs are significantly different from thosein the water that the body was found in, it may also mean thatthe victim has been deliberately drowned elsewhere and movedto the second location to make the cause of death seem accidentalor even suicidal.

Research has demonstrated how diatoms can be used to estimate the time since death, whichis a crucial piece of information in any forensic investigation. This is notoriously difficult to

do in cases where the body has been found in water, with scientists often drawing conclusionsbased on the body’s level of decomposition and the presence of insects and bacteria. Thiskind of work remains largely fixated in trial and error, but it is useful for establishing a

timeline since submersion and or death in water.

criminal evidence

Lost & Found

The reason why diatoms are becoming so useful in regards toforensic science is that they are so bountiful in differentenvironments. Microscopic assessments of algae found onclothing, footwear and personal belongings have already beenused as evidence in cases including homicides, assaults, andburglaries across the US and Europe.

Case Closed

The collection of diatoms in a victim’s bone marrow represents a microbial“fingerprint” of the time and place where drowning occurred. Each lake,river, and estuary contain a unique community of diatoms. The mix ofspecies found in any given location also fluctuates over time, and varies

according to the season.

F O R M O R E I N S I G H T S O N F O R E N S I C S C I E N C E A N DI N N O V A T I O N S I N T H E F I E L D

F O L L O W M E

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