Nisa Celik
Unit 23: Forensic Evidence, Collection and Analysis
Learning Aim A Understanding how to gather forensic evidence 2024
Decision makers make a decision based on the documentation of the investigation. The
information contained in the official report must be proven by investigation. Investigative actions
must be effectively documented. Otherwise, the incorrectly written report may negatively affect
the investigation and lead to a wrong decision. There are different methods for documentation.
Crime Scene notes are a detailed record of the crime scene and the actions taken during the
search. Crime scene notes can be used as evidence in court and help the crime scene expert
accurately recall the actions.
A crime scene sketch shows the general plan of
the crime scene and the relationships of the
evidence with the environment. Can be used
when questioning suspects and witnesses.
Photographs taken at the crime scene clearly
show the crime scene and are therefore used in
court.
Crime scene photographs will harm the
investigation if they do not fully and accurately
document the entire crime scene.
Evidence labels: The crime scene investigator labels and marks the evidence he collects. This
allows this evidence to be separated and easily identified at a later date.
cordon log ensures that no one can enter the scene to prevent evidence from being lost and to
ensure security.
A record is kept of everyone who enters the scene, detailing why they are there and the dates
and times they arrive and leave. Case file contains evidence and documents related to the case.
For this reason, the case file is very important. In order for the case to be concluded and the
correct decision to be made, the case file must contain all the details about the incident. Case
files contain content related to a specific action, event, person and place.
Laboratory examination is used by forensic scientists to record details regarding the forensic
examination of items of physical evidence submitted to the laboratory. This physical evidence is
collected by crime scene investigation teams.
Documentation is also of great importance in examining the crime scene and concluding the
investigation in court. The methods mentioned above are used for documentation. Unsuccessful
and inaccurate documentation adversely affects the course of the case and affects the decision
,of the decision makers. Incorrect or incomplete documentation makes it difficult to resolve the
incident. Therefore, the court may make a wrong decision.
Proper collection and packaging of evidence is important for the successful completion of the
case. There are certain steps that must be taken to ensure that evidence is handled
appropriately. First of all, it is necessary to ensure the safety of the crime scene by protecting
personnel from potential dangers associated with evidence. Evidence must be protected against
loss, destruction or contamination. For example, recording footprints before they are lost or
contaminated is very important for the course of the case. Evidence must be accurately
identified and recorded in official documents and ensure that it is secure. The appropriate
method for collecting and packaging evidence should be determined according to the type and
condition of the evidence. This way, evidence can be collected without being damaged.
There is a lot of physical evidence that can be taken from the scene of the crime. Examples
include:
-Biological evidence (blood, body fluids, hair, etc.)
-Hidden print marks (fingerprints)
-shoe and tire marks
-drug evidence
-weapon evidence
-trace evidence (glass shards)
Biological evidence determines the collection and packaging procedure according to the
condition of the evidence. Examples of biological evidence include blood, hair or saliva. If there
is bloody clothes in the case, the blood-stained clothes are packaged in breathable paper bags
or boxes. The blood stain should not spread to other parts of the garment and it should not
wrinkle. Evidence must be packaged separately. Crime scene investigation tracks small-sized
objects such as glass particles. Once identified, precautions must be taken to preserve
evidence. To collect evidence; Different techniques such as lifting, digging, vacuuming and
scanning can be used. Equipment such as tweezers or spatulas can be used to collect such
evidence. This trace evidence should be placed in a container such as a glass bottle or can.
Evidence such as weapons should never be packaged fully. because this may pose a great
danger to laboratory workers and those around them. The gun must be unloaded by a specialist
and properly packaged in a box to protect any marks on it.
, Scene of Crime Officer (S.O.C.O) is an officer who gathers forensic evidence at the scene of a
crime. SOCO comes to the area and interviews the victim, if any, to develop theories. This gives
clues about what happened at the scene and helps create a theory and the initial investigation is
carried out. Then the documentation phase begins. SOCO looks for evidence to determine
whether the theory is supported. At this stage SOCO provides photographs, sketches for
documentation. These give more information about what happened at the scene. Places where
evidence is found should be photographed from many different angles. This way, nothing will be
overlooked. The photographs, sketches, and notes SOCO uses to accurately record the crime
scene create a detailed record of the crime scene investigation. Evidence is a very important
element for the investigation of the case. It helps the court make a decision and punish the
criminal. For this reason, it is important that evidence is collected and packaged correctly.
Inaccurate evidence may lead to a wrong decision, the release of the accused, or the arrest of
the innocent.
Scientific Support Unit (SSU) refers to forensic
scientists who support the agency in collecting
crime scene DNA that links the criminal to the
crime and location, which is often critical in court
cases.
SSU provides support and assistance in carrying
out research, scientific production and clinical
practice requirements. The purpose of SSU is to
assist in the detection of criminals and to
maximise registered crimes.
Crime Scene Investigators (CSIs) are law enforcement officers or specially trained members
who collect physical forensic evidence at the crime scene and use scientific methods and
technology to assist in the investigation of the incident to process and interpret the evidence.
The crime scene investigator is responsible for identifying, preserving and packaging physical
evidence. CSI has some important roles, namely: