Introduction to Physical Evidence

Physical evidence plays a vital role in the field of forensic science, serving as a tangible link between the crime scene, the victim, and the perpetrator. It encompasses a wide range of objects and substances, each capable of providing crucial insights into the circumstances surrounding a crime. From biological materials such as blood and hair to inanimate objects like weapons and documents, physical evidence not only helps establish that a crime has occurred but also assists law enforcement in identifying suspects and reconstructing the events of the crime. Understanding the different types of physical evidence and their significance is essential for anyone interested in the intricacies of criminal investigations and the principles of forensic science. This exploration of physical evidence will provide a comprehensive overview of its types, analysis techniques, and the invaluable information it yields in solving crimes.

What is Physical Evidence?

✔ Physical evidence is any object that can establish that a crime has been committed or can link a crime and its victim or perpetrator.
✔ Anything can be physical evidence that can connect the crime scene to the criminal.
✔ “In simple words, to count physical evidence cannot be possible.”

🔦Types of Physical Evidence

1. Body Material

Body fluids or materials found at a crime scene might include:

🔘In case of poison, the main parts of the body, such as the Liver, Gall bladder, Brain, Kidney, Small intestine, Pancreas, Uterus, Heart, and Lungs, should be analyzed.

🔘Blood, Semen, Saliva and Vomit in dry or liquid state.

🔘Hair, Nails, Skeleton, Bone.

2. Botanical Matter

🥦Plants
🍇Fruits
🍉Seeds
🌿Leafs
🌴Wood, etc.

3. Chemical Substance

🚫Explosive (any object that has a residue of an explosive is practical.)
⚫Alcohol
⭕Paint
💊Drugs, etc.

4. Weapons

✔Firearms
✔Pistol
✔Revolver
✔Gun
✔Bullet
📍Cover, etc.
🔑Other arms, such as;
🗡Knives
⛏Axe
🏹Arrow
⚔Sword
🔨Hammer
✂️Scissors
🏉Stone, etc.

5. Disputed Documents

Examinations and comparisons conducted by document examiners can be diverse and may involve the following:

Typewriters, photocopiers, printers, fax machines.
Handwriting (cursive / printing) and signatures.
Alterations, additions, erasures, obliterations.
Indentation detection and/or decipherment.
Cheque writers, rubber stamps, markers.
Physical matching.
Ink, pencil, paper

6. Petroleum Substances

⚫Any type of petroleum substance that is likely related to a criminal act. Such as: kerosene oil, petrol, etc.

7. Tool Marks

⭕Tool mark as any impression, cut, gouge, or abrasion caused by a tool coming into contact with another.

⭕They consist of small, commonly microscopic, indentations, ridges, and irregularities present on the tool itself. For example, the tip of a screwdriver is never perfectly flat, but shows small ridges along its edge.

8. Impression

✴ Fingerprints
✴ Tier marks
✴ Footprints
✴ Shoeprints etc.

9. Fibers and Textile

🧤In Many Cases, Clothes And Rope Are Used In Many Forms.
📜Natural fibers
📜Artificial fibers
📜Threads
📜Ropes
📜Clothes

10. Soil

🔅Sand
🔅Clay
🔅Slit
🔅Peat
🔅Loam
🔅Chalk
🔅Whichever stick with Tiers, Mudgaurd, Shoes, Clothes, etc.

11. Glass

Pieces of glass, such as:
🔎Any Window/ Glass Door
🔎Glass bottle
🔎Watch
🔎Spectacles

12. Objects Of Criminal

📃 Identity Card
📒Diary

13. Other Evidence

◾Any other substances found on the crime scene not described before in previous slides should be considered in this category.

◾For example, after the collision of a new building or bridge, a sample of debris is physical evidence.

◾Things that have numbers. Like, engine, chesis, etc.

Information that can be obtained from Physical Evidence

📍Corpus Delicti

⚀ The Latin term corpus delicti refers to the principle that there must be some proof that a crime has been committed before a person can be convicted of that crime.

⚀ Corpus delicti literally means body of crimes.

📍Identification of suspect

Fingerprints are valuable evidence to identify and individualize a suspect.

📍Linking suspect with victim

At the time of the crime, blood, hair, fiber, etc., can be exchanged between the suspect and the victim, which establishes a connection.

📍Linking of suspect with scene of crime

Fingerprints, shoeprint or footprint, blood, semen, fiber, hair, tool marks, tire impression, bullet, soil, etc, are evidence that can establish links from suspect to scene of crime.