Principles_of_Forensic_Science_Presentation.pptx

1. Principles of Forensic Science
Comprehensive Overview

2. Introduction to Forensic Science
• Definition: Application of scientific principles
and techniques to criminal investigations.
• Aims: Assist law enforcement, establish facts,
ensure justice.
• Scope: Covers various disciplines including
biology, chemistry, physics, and digital science.

3. Principle of Exchange (Locard’s
Principle)
• Every contact leaves a trace.
• Whenever two objects come into contact,
material is transferred between them.
• Basis for trace evidence examination such as
hair, fibers, glass, and soil.

4. Principle of Comparison
• Unknown samples must be compared with
known standards.
• Used in fingerprint, handwriting, and ballistic
analysis.
• Ensures reliability of identification and
authentication.

5. Principle of Individualization
• Every object, person, or substance has unique
characteristics.
• Fingerprints, DNA profiles, and tool marks
serve as examples.
• Individualization strengthens identification in
forensic cases.

6. Principle of Probability
• Forensic conclusions are often based on
probability, not certainty.
• Statistical methods used in DNA profiling,
population studies.
• Helps establish likelihood of involvement or
exclusion.

7. Principle of Analysis
• Systematic collection, preservation, and
examination of evidence.
• Following standard protocols and scientific
methods.
• Maintains accuracy, repeatability, and
objectivity of findings.

8. Principle of Circumstantial Facts
• Circumstantial evidence can establish links
between crime, victim, and suspect.
• Examples: fingerprints on weapon, footprints
near scene.
• Requires corroboration with direct evidence
for stronger proof.

9. Principle of Law of Parsimony
(Simplicity)
• The simplest explanation consistent with facts
is preferred.
• Avoids overcomplication of evidence
interpretation.
• Supports logical and objective crime
reconstruction.

10. Principle of Evidential Value
• Each type of evidence has specific probative
value.
• Direct vs circumstantial evidence: different
weight in court.
• Value depends on relevance, reliability, and
admissibility.

11. Principle of Multiple Approaches
• Use of multidisciplinary methods for analysis.
• Integration of biology, chemistry, physics, IT,
and psychology.
• Ensures comprehensive understanding of
evidence.

12. Principle of Chain of Custody
• Continuous documentation of evidence
handling.
• Prevents tampering, loss, or contamination.
• Ensures admissibility of evidence in court.

13. Principle of Reproducibility and
Repeatability
• Forensic tests must yield the same results
when repeated.
• Independent verification strengthens
credibility.
• Crucial for scientific acceptance in court.

14. Principle of Ethical Practice
• Forensic experts must maintain integrity and
impartiality.
• Avoid bias, ensure transparency, and uphold
justice.
• Follow ethical codes and legal standards.

15. Conclusion
• Principles of forensic science provide the
foundation for accurate investigation.
• They ensure evidence is handled scientifically,
ethically, and legally.
• Adherence to these principles enhances the
reliability of forensic science in the justice
system.