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Crime Scene Investigation

Crime Scene Investigation

A crime scene is place where an offence has been committed and the investigators carefully examine or search the area in order to find probative evidence. The purpose of crime scene investigation is to establish the possible link suspect, victim, witnesses in relation to criminal event.

In the majority of cases such as homicidal, suicidal and accidental, the crime scene investigators as well as law enforcement officers play a significant role in determining proper collection as well as preservation of physical evidence which might be accidently left by the criminal. Proper documentation and photography of a crime scene should be done by specialised and well-trained personnel that could help them to reconstruct the crime scene.

A well-trained crime scene investigator (Investigating Officer) must following basic steps in order to perform proper investigation to maintain the chain of custody:

1. MedicalAssistance to the victim if there is even a remote chance of life.

2. Securingthe crime scene by barricading using barricading tape, rope or cones etc. to protect the entry of unauthorized persons like on lookers, family members, witness etc.

3. Documentationof the crime Scene

a. Photography/Videography (Over view, Mid-range and close up photography)

b. Note Taking (Complete description of the crime scene)

c. Sketching of the Crime Scene (Rough and Final Sketch)

4. Searching of the evidences

a. Strip or line search method

b. Grid Search Method

c. Spiral Search pattern

d. Wheel or Ray search pattern

e. Quadrant or Zone Search pattern

5. Collection of Physical Evidences (Following evidences should be sent to Forensic Laboratory):

a. Victim’s Clothing

b. Fingernail Scapings

c. Hairs (head or pubic hairs)

d. Gun/Bullets recovered from the crime scene or victim’s body

e. Hand Swabs from Shooting victim (for gunshot residue analysis)

f. Semen/Vaginal/Anal/oral Swabs in case of sex related crimes for DNA Profiling

g. Blood/Viscera Samples in case of poising cases

h. Debris collection in case of arson/fire cases

6. Preservation of evidence by-

a. EDTA for blood samples

b. Air dry method

c. NaCl Solution for preserving viscera

7. Packaging of Evidences should be done using

a. Unbreakable plastic pill bottles with pressure lids (hair, glass fibers)

b. Manila envelops

c. Screw cap glass vials

d. EDTA tubes for fresh blood

e. Sealable plastic bags

f. Druggist Fold

g. Paper bags

h. FTA card for collecting DNA sample

8. Naming and Tagging of evidence (complete description of the evidence)

a. Nature of evidence

b. Name of the investigating officer

c. Person collected the evidence

d. Initials of the investigating officers

9. Forwarding Letter in order to send the evidence to the Forensic Science Laboratory.

10. Releasing the Crime Scene for general Public or Family members.

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Comments

  • Eli Richardson | Sep 8,2021

    I found it interesting when you talked about how crime scene experts and how they investigate one. In my opinion, it must be tough to deal with such intense criminal scenes. I believe if I were to hire a crime scene investigator, I’d look for a highly trained one to provide a quality job. Thanks for the information on how an investigator evaluates a crime scene.

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