FIRST RESPONDERS AND PHYSICAL EVIDENCE

There are generally two types of evidence present on a scene, subjective evidence and physical evidence:??

SUBJECTIVE EVIDENCE?

This evidence can be gathered from human sources such as victims, complainants, eyewitnesses and suspects. This can be done in the form of descriptions, statements and confessions.

WHEN ENGAGING WITH HUMAN SOURCES THE FIRST RESPONDER MUST ALWAYS RESPECT THE HUMAN RIGHTS OF THAT INDIVIDUAL WHILE TRYING TO OBTAIN INFORMATION ABOUT AN INDIVIDUAL, INCIDENT OR EVENT!

PHYSICAL EVIDENCE

This evidence is visible, recognisable and tells a story. I.e. firearms, ammunition, plastics, ropes, personal computers, documents, finger prints, blood, bones, corpses, insects and plant species.

REMEMBER IT IS NOT THE FIRST OR SECOND RESPONDER’S RESPONSIBILITY TO PACKAGE OR ANALYSE ANY PHYSICAL EVIDENCE THAT MIGHT BE PRESENT ON THE SCENE!?

FRICTION RIDGES “FINGERPRINTS”?

Fingerprints are impressions left by the friction ridges of human fingers. A fingerprint provides a good chance of solving a crime due to the sheer volume of fingerprint records available in stored databases around the world (also known as biometric data).

The use of fingerprints dates back to 3300 BC in ancient China where fingerprints were used on clay tablets as seals. Knowledge about fingerprint’s unique nature haven’t surfaced in Europe until the mid – 1800’s when Jan Evangelista Purkinje published a thesis at the University of Berslau that identified the different types of patterns found on friction ridges. It wasn’t until the turn of the previous century when Sir Edward Richard Henry created a classification system that is still being used by the Federal Bureau of Investigation (FBI) in the United States till this day. This classification system gave rise to the science of Ridgeology and Edgeoscopy that we know today.?

DUE TO THE UNIQUENESS OF EVERY FINGERPRINT FIRST AND SECOND RESPONDERS MUST TAKE GREAT CARE (WHERE REASONABLY PRACTICAL) NOT CONTAMINATE OR FLOOD THE SCENE WITH DEPOSITS OF THEIR OWN PRINTS!

Proper training in basic scene management and the sterile methods it demands must be retrained annually.?

Fingerprints can be divided into three categories:

1.???????Patent: Visible to the naked eye. Made by an extra substance on the skin and transferred to a surface like windows, alcohol bottles or knifes.

2.???????Latent: Not visible to the naked eye. Made by oils and salts from the skin and transferred to a surface like firearms, door handles or vehicle paneling.

3.???????Impressed: Visible to the naked eye. Made by pressure applied to a moldable surface like wax, wet paint or blood.?

Fingerprints can’t be borrowed, stolen or forgotten. If a set of prints are present on a scene so was the person that left it!

DEOXYRIBONUCLEIC ACID “DNA”?

The past decades have seen great advances made in a powerful tool called Deoxyribonucleic Acid “DNA”.?Developed as the “DNA fingerprint” by Prof. Alec Jeffreys in England during the mid 1980’s this technology have been employed in the legal field and beyond.?

Tissues and fluids in the human body are built up of microscopic cells.?These cells have something in common called Deoxyribonucleic Acid. This Deoxyribonucleic Acid can be studied under a microscope and if found to be a match used to identify criminals with incredible accuracy.

DNA does not only help to place a suspect at a crime scene but also helps forensic genealogists to solve cases that went cold decades ago. It is extremely important to remember that a suspect doesn’t have to bleed at a scene to leave their DNA behind and that DNA can survive much longer than a fingerprint.

Collecting biological evidence at the scene, from a victim or suspect by method of blood, fingernails, hair, saliva, urine, sweat stains, clothing or on ropes must only be done by trained and authorised specialist. So much evidence can be found on and inside of the human body that it constitutes a crime scene unto itself

FIRST AND SECOND RESPONDERS SHOULD ONLY TAKE NOTE OF ALL THE PLACES BIOLOGICAL EVIDENCE MIGHT EXIST AND BE EXTREMELY CAREFUL NOT TO CONTAMINATE OR DESTROY ANY BIOLOGICAL EVIDENCE PRESENT ON THE SCENE.

Under no circumstances may a victim of any sexual violation be interrogated on the scene by any member of any service; public or community based.

FORENSIC ANTHROPOLOGY “BONES AND CORPSES”

Forensic Anthropology is associated with bones and corpses (victim or suspect). The value of this evidence is based on identification and wound construction i.e. blunt, sharp or high velocity force trauma.?

A corps will decay in five stages:

1.???Initial Decay: The corps appears much as it did in life (externally) although decomposition has begun (internally).

2.???Putrefaction: Gas forms within the corps and cause it to swell and smell.

3.???Black Putrefaction: The swelling of the previous stage (putrefaction) collapses. Gas begins to escape. Swelling decreases and the smell increases.

4.???Butyric Fermentation: Organs and flesh has become fluid and has escaped. The corps begins to dry out (desiccate). ?

5.???Dry Decay: Flesh continues to dry out. Slowly shrinking until only the skeleton is left (skeletonization).?

Each stage of decay plays an important role in the establishment of a possible timeline and serves as an indication of the type of injuries that might have lead to death!

FIRST RESPONDERS MUST UNDER NO CIRCUMSTANCES MOVE ANY BONES OR CORPSES DISCOVERED!?

FORENSIC ENTOMOLOGY “INSECT SPECIES”

The use of Forensic Entomology is associated with insect and their life cycles. The value of this evidence is based on post-mortem intervals (time or date of death).

In China during 1247 AD when a victim had been stabbed repeatedly investigators suspected the murder weapon to be as sickle. A common tool used by thousands of people in the area to harvest rice. To identify the murder weapon from those used by other workers in the area the local magistrate brought all the workers together and told them to lay down their sickles. Though all the sickles looked clean, one quickly attracted hoards of flies. These flies could sense the residue of blood and tissue invisible to the naked eye. When confronted by this “jury” of flies, the murderer confessed to the crime.?

Knowledge pertaining to the existence of insects in bodies only started to surface in the late 1700’s after a doctor named Reinhard exhumed bodies and noted the presence of Phorid flies. This lead to scientist in the 1800’s to study the insects that would inhabit decomposing bodies.?

These days not much has changed and forensic entomologists will connect a particular stage of death with a particular type of insect infestation that makes it possible to determine if a body was available or unavailable for insect infestation.?i.e. moved from the scene of the crime to the crime scene. ?

FORENSIC BOTANY “PLANT SPECIES”

Forensic Botany also known as plant forensics includes the analysis of plant and fungal parts i.e. leave flowers and seeds. These botanical specimens will then be studied underneath a microscope and linked with a crime scene. Humans live in a world where animal and plant introduction takes place on a daily basis. As a victim or suspect moves through time and space it is highly likely that they will have pollen somewhere on their person. Minuscule plant particles that are invisible to the naked eye can cling to material for years or even decades. 1935 marked the year when the first crime was solved using forensic botany. These days comparing botanical specimens to thousands of known specimens already in a database is easier than before to identify the botanical “DNA” and use it as evidence in court.

TO TAKE ADVANTAGE OF THIS EVIDENCE, COLLECTION MUST ONLY BE DONE BY EXPERTS TO COMBAT ANY CROSS CONTAMINATION THAT MIGHT OCCUR!

In conclusion, the contact theory argues that a criminal will always leave something behind for the expert eye to search for find and analyse. Crimes are committed by people and in doing so they make mistakes, these mistakes are called clues. Clues will only turn into evidence when it is recognised, protected, collected, packaged accordingly, submitted for analysis, and finally presented in court as evidence by trained and authorised personnel.?

IT IS NOT THE FIRST OR SECOND RESPONDER’S RESPONSIBILITY TO SEARCH OR PACKAGE PHYSICAL EVIDENCE THAT MIGHT BE PRESENT ON A SCENE!