with serious injures left lonely
stretch on rare area from the
city. A fire broke out at a lawyer
office just one day before the court. A
car accident leads to claims the life of
whole family . All previous cases are
probable a crime scene.
establishing methodical examination for the previous incidents , investigators should be systematic at crime
scene while searching for physical
evidence which can arrest the penetrators. Also, this process must be bone with
care in order to preserve the decisive
evidences from damages.
At the scene
the first officer arrived is responsible for defining the scene or evaluating the scene,
establishing a systematic plan for collecting evidence without desiring them, secure the scene that is potential contain a critical evidence,
recording the scene and determining the involved people in the case and
packaging and submissions of evidence to
report we are going to provide related information to crime scene investigation ::
investigation is the meeting point of science , logic and law. It is a process
that include purposeful documentation of the
conditions of the crime scene.
Also, it include the collection of any physical evidence that could explain what happened and who did it.
If we take a look at who is
presenting at crime scene?:
The first who
arrive at a crime scene. They arrest the perpetrator if still around
and call for an ambulance if necessary. They are responsible for
securing the scene so no evidence is destroyed.
Who documents in a detail everything in the crime scene and
collects any physical evidence.
They present in case of homicide
to determine a cause of death and not always present.
They interview witnesses and
conduct with the CSI unit. They investigate the crime rely on witnesses and physical evidence. 5.
A highly trained professionals who analyses the evidence from a crime scene and present findings basing on the
results of their analyses. The common
works of the technician are:
-Collect, process, and analyze
-Collect physical evidence
such as weapons.
-draw crime scene sketches.
-determine which items
should be collected at the crime scene
-List the evidence and prepare it for safely transpotation to the
photos of the whole crime scene.
Including entomologists, forensic
scientists and forensic psychologists to
analysis the evidences.
we talked in detail about the duties of
forensic scientist :
laboratory examination and analyses submitted by
-Serving as expert
witness in a
court of law.
out tests using scientific
techniques such as
spectrometry and scanning
laboratory protocol and
regulations are followed.
putting data into
computer programs and
data base Information.
activities related to
crime scene collection
preservation and transportation.
-Serving as lesson between the
forensic laboratory and
crime scene Investigators.
and updating work quality
standards and operating
with other members
of forensic term
and without side.
Forensic scientists usually perform
their work in forensic or crime laboratory . They are responsible for comparing
and interpreting the physical evidence that was brought by crime scene investigators. In specific
circumstances, forensic scientists may present at the crime scene when the techniques of the collection or preservation of the
physical evidence are in question.
Types of crime scene:
crime scene is the surrounding area
where a crime has been committed. Such as forest, road, house or it could be
any place. Crime provide clues that help in solving
the crime which was committed.
scene can either be primary or
secondary. Primary scene is a scene where the actual crime took place. For example , in a murder
Investigation , the primary scene would be the place where the murder occurred
and the reason’s life was taken. In addition,
there might be additional crime scenes involved as well and it would be the
secondary crime scene. For instance , the criminal may have changed the place
of the body after the murder. Let’s say the body was removed and placed in a forest then it would be the secondary crime
scene. Secondary crime scene can help in finding more evidence which help in
solving the case.
method to a crime scene investigator:
The successful certainly
observations that the investigators found can be determine by the obtained
results of the crime scene. The CSI should be methodical, reasonable and should
are the physical evidences at the crime scene?
procedure to protect and collect these evidences.
approach of how to obtain observations from these evidences.
linking all the obtained results.
versus individual features :
The investigator of the crime scene
should have the ability to differentiate between the class features of physical
evidences and the individual. It is not
possible to identify all the physical evidences by only linking them to a
related item or person. Therefore, the
crime sense investigator (CSI) have the responsibility to discuss all the
results of his forensic analysis with the scientist of the crime laboratory
(lead detective) to find a cohesive and objective presentation of the evidence.
Furthermore, biological or physical evidences can be included in the class or
individual features and sometime exclude persons from the investigate
It is not necessary that the physical evidence is related to a
common origin with a high degree of certainty, hence, only a group of sources
can only be located into a class and not a single. For the differentiation
between the class evidences, it is not always possible for the investigator to
find the exact or estimated probability values. A good example of class
evidence is the polyester fibers.
Investigation will collect information concerning the makeup polyester fiber, but it is not possible to state
affirmatively that the fibers came from a specific rug. In addition, significance can be included to
the place and amount of the fibers regarding the murdered, suspicious and/or
crime scene. However, the investigators cannot accurately suggest that a specific
rug was the source of the fibers.
Individual characteristics are
generally considered as measurable differences evidences( physical and
biological) which permits it to be related to a single source with a high level
of accurately. This allows the investigators to identify the uniqueness of any
single item of evidence. The mathematical likelihood which there are 2 matching
sources of the distinct evidence of individual is beyond human understanding .
The forensic examiner can illustrate in the court the scientific outcome which
excludes the probability of two identical sources of evidences (biological or
Direct evidence means that no need
of further investigation due to an established fact. A good example for the
direct evidence is a recorded video of theft shop where the victim’s face is
clear and easy to be identified or the permit of the eyewitness who was in the
shop at the time of the shop robbery. Therefore, direct evidence does not
need inference or hypothesis. It depends
to the knowledge or perception of the investigator and then directly confirm or
disconfirm the disputed fact.
Circumstantial evidences are the
most evidences that are examined in the forensic laboratory, and it is depends
to the forensic scientist to illustrate an inference of his analysis to provide
the fact. Therefore, this type of evidence is relies on reasoning and not
direct inference of a fact. To conclude, Circumstantial evidence is when the
knowledge can be inferred from witness at trail.
Chain of custody:
At the crime place, all the
information of the crime scene includes individuals, action, permit, and the
investigation documents an important link in the chain of custody. Chain of custody is a formal paper in order to
preserve the physical evidences. Starting with the arrival of the investigators
and the emergency people at the location of the crime scene, different
activities are scrutinized by hundreds of people with different roles in order
to ensure that the justice is achieved.
The protective procedures must be
done immediately at the place of the crime scene in order to protect all the
evidences. Then, the access to the crime scene should be controlled and the
investigation procedure begun.
The chain of the custody illustrates
the transformation of the physical
evidences from the place of the crime scene until the investigator releases the
crime scene ……..of the disposal of the evidence.
To lab for analysis.
By property/evidence unit
At the scene by CSI; entered on log and secures.
To properly/evidence unit for storage
To CSI for court presentation
To property/evidence unit to await disposal
Be returned to owner or destroyed (court determination
scheme 1: chain of custody
Figure 1: shows chain of custody.
Crime scene technicians are in charge of providing a systematic strategy for Searching for physical evidences in order to preserve them from contamination
and damages and to cover up all types of evidences. Therefore for each type of area there is a unique
pattern should be followed to achieve
The patterns the used in crime scene
method: all most this method applies for
large areas which contains tiny
individuals in search.
-Grind search method: it is also used for
large areas that contains a abundant number of searchers. Also, it is often used in open and woodland areas.
-Line search method: this
pattern used in moderate area with a few number of searchers.
search method: this method used for small areas.
Figure 5: shows search patterns
Recording is one of the critical and significant procedures
in crime scene investigations for
many reasons. It is important since it
can help investigators to gain a comprehensive overview and inclusive knowledge about crime scene.
For instance, it can provides a
reliable material evidence according to
their position and inter-relation to scene as well as, it can provides
witnesses with ability to indicate the position of people and things within
scene and time of crime . finally, it
can support the court restricting the scene in details with potential evidence as well as refreshing
memory of assessor of any incident.
Recording crime scene can be done
by photographs, notes and plans.
Photography is one of the most significant methods that
used for recording crime scene due to its ability to provides a virtual
reality picture for an incident.
Although, it can be useless or excluded by the court
in case that is taken after any change
made at the scene therefore, the most
requirement for photography is the crime scene should be in unaltered
Photographs should include:
-Primary crime scene and the adjacent area of area that incident
-All objects at the scene which can be used in investigation.
walls within the place that crime
taken place and walls of adjacent place.
-Weapons used , surface under corps
and blood stains.
-The relative position of objects as
well as body with adjacent items in the
Figure2: recording crime scene by photography.
the purpose of writing notes is to provide an inclusive and certain records about observations , sequence of events and examination of crime scene. Notes which written at the
time of incident may be it is not at logical
sequence but that producible and can be fixed later on be reorganizing sequences in report. In
addition, notes of events and
observations maybe become non-significant or meaningful if it is written
without indicating to some important details which is in relation with incident
such as ( when, where, by whom , how…)
therefore, notes should include:
and date that investigators arrived.
person arrived at crime scene.
who was in charge about this case.
is the incident and what was
and activities taken place.
Investigators are in charge of
Preserving evidence therefore, they
shroud concern about their movement
pathway while writing notes at
crime scene in order to keep evidence without damages and
Plans are complement details of notes and photographs as well
as it provides specific details about
dimension and an overview for scene by showing scales and the exact
position of items that related to the
scene. There are several methods used to
plans crime scene, Floor –plan is one way of
planning both outdoor and indoor
crime scene which illustrate the
location looking down from above. For instance, cross-projection or exploded
view is very close to floor-plans but it
vary in walls that folded to uncover
items that founded in the walls. Isometric projection sketches also used to
indicate items of physical evidence like bloodstains. 3D or tree-dimensional
sketches are new methods used in crime scene investigations which gives a
virtual reality picture for the
However the most common plans used
for crime scene investigation:
plan ( rough sketch) :
plan that drown at crime scene by investigators in order to show the position
of items and their relations with another items.
or appearance of items in sketches by indicating each item by a number or a
letter and provides a ligand for items.
should include time, date, and description of the crime.
Figures3; shows rough sketches.
plan (fished sketch):
Scale plans sketches with accurate dimensional size, shape
and position .it considers more accurate an sketch plan since it is
concern about artistically view or appearance, accuracy and it is drown with scales.
Figure4: shows fished sketches.
Collection of evidence
Crime scene investigation depend on the collection and the analysis
of different type of evidence. There are physical and biological evidences. The
physical evidence is any nonliving items and the biological evidence refer to
any living being. Also, there is another important type of evidence called
impression. Impression is a patterns of the items when it contact with soft
surfaces like shoes patterns. The collection of impression which found in crime
scene is very helpful and important to the investigation. According to Locard’s
Exchange principle that perpetrator when
enter a room he must leave something during contact with object or victim, and
at the same time he must take something with him.
There are many different
types of evidence that can be collected from the crime scene such as :
, hair ,body fluids and many other tissues.
Blood should be
collected in clean gauze pad or clean sterile cotton and allow to dry at room
temperature. Also, it should be
refrigerated and frozen and send
to laboratory as soon as possible. If there is dried blood on clothing, first
wrap the item in clean paper then place it in brown paper bag, seal and
label the container and never try to
remove the stains from the clothes.
adhered to a piece of film and sealed with polythene bag.
Figure 5:collect blood sample by clean sterile
Including palm print, fingerprint and footprint.
The collection of impression evidence need forensic specialist and
can’t just packed directly because it can be easily destroyed.
Fingerprint is the most important evidence which gives direct individual
information because no one have the same fingerprint even the identical twins. Dusting
fingerprints with special chemicals is a way to collect latent print.
Figure 6:collection fingerprint by
Including fibers, glass fragments and soil.
Wrap the glass and fibers separately in clean paper( envelopes)
with lapels and send it to the laboratory for test.
Including cell phone records , emails and internet logs.
Electronic devises , charges , cables and manual should be
collected. Also, cell phones, thumb drives and hard drives should be collected
and examined by different tools and techniques in specialized lab.
Drug collection is based on the type of the drug. For instance,
plant should not be packed in plastic because of the moisture and mold growth.
And if the drug is in syringes or other sharp object it should be packed hard
sided packaging like cardboard cartons or glass vials then labeled the
Figure 7: use glass tubes to
-Never send a loaded gun to the laboratory unless it’s taken in
person. Also, firearm should never be shipped even if it is not cocked or on
-never shot from the gun before it is being examined in the lab. What is more, the firearm should not be cleaned the bore ,
cylinder or chamber before submitting
– do not place
pencil or any object in the end of the barrel when pick up a firearm.
– record the caliber ,model ,make and serial number of the firearm.
– firearm should be packed and place in strong wooden box or cardboard to make
sure that the weapons will not shift during the transition.
– gunshot and rifles should not be taken separately.
Figure 8: gun collected in plastic
crime scene safety:
This may refer to the procedures
followed to control crimes there must be proper equipment to process the scene
depending on the situation to protect the body. The scene has to be secured and
protected before you process it ,this is for the safety of the crime scene
officers and everyone else. The first one is to put on latex gloves which are
important for protecting evidence because they keep you from leaving finger
prints behind. They offer you protection from blood and other substances at the
scene so remember to cover your shoes or boots with rubber boots when you are
indoors. Photograph the shoes of everyone at the scene including the officers
and the technicians, so that you can distinguish their imprints from those of
suspects. Pay attention to the types of shoes or boots you wear they must have
a good attraction and ankle support and will offer you protection from hazards
such as nails. A helmet is also important they light and easy to store and eye
protection there might be chemicals processed depending on the situation.
Figure 9: wear latex gloves to
protect you from dlood contaminations , diseases and protect you from bieng
suspecious by lnot leaving your fingerprint.
Personal protective equipment (PPE)
at the crime scene is very important for
the crime scene investigator and they should take it into consideration in
order to protect themselves from any hazards that may occur at the
investigation place. PPE may include wearing gloves, shoe covers, full body
suits and safety glasses. The first responders at the crime scene should
immediately ensure that there is no threats to the investigators in the crime
scene. Therefore, preventive measure must be followed in order to reduce the
threat of any accidental contamination.
This report gives important information about crime scene
investigation. The persons who present in crime scene and their exact jobs.
Moreover, the different types of crime scene (primary and secondary). Also, it
shows information about the important procedures before starting the
investigation such as approaching , medical assistant and crime scene securing.
In addition, it gives all the important information about the whole investigation procedures and the crime
.The Practice of Crime Scene Investigation ,
by John Horswell.
.Techniques of Crime scene Investigation,
Eighth Edition , by Barry A.J Fifher,daived R. Flasher.
.Crime Scene Investigation, by Jacquelline
T. Fifh,Larry S. Michael C. Braswell, Edward W Wallace.
Julia. “How Crime Scene Investigation Works.” HowStuffWorks Science,
HowStuffWorks, 2 Dec. 2005, science.howstuffworks.com/csi.htm.
-“CSI Job Description.” How to
Become a Crime Scene Investigator, www.crimesceneinvestigatoredu.org/job-description/.
to Become a Crime Scene Technician: Career and Salary Information.” Criminal
Justice Degree Schools,