Forensic_Chemistry_Chapter1_Presentation.pptx

1. Introduction to Forensic
Chemistry and Toxicology
Chapter I Overview
Presented by: Jomar P. Deray, MAEd

2. What is Forensic Chemistry?
• Forensic Chemistry is the branch of chemistry
that applies chemical principles to solve legal
problems.
• Role:
• It helps clarify legal issues through scientific
investigation.

3. Scope of Forensic Chemistry
• - Criminal investigations
• - Legal medicine
• - Ballistics
• - Questioned documents
• - Dactyloscopy
• - Photography

4. Development in the Philippines
• Key Milestones:
• - 1876: Medicos Titulares created
• - 1887: Laboratorio Municipal de Manila
• - Present: Four main forensic labs (NBI, MPD,
CID, PNP)

5. Scientific Evidence
• Evidence requiring scientific knowledge to be
understood in court.
• Types:
• - Physical
• - Direct
• - Circumstantial
• - Hearsay (with exceptions)

6. Forms of Scientific Evidence
• - Real/Autoptic: Sensory-based
• - Testimonial: Oral witness statements
• - Experimental: Demonstrations
• - Documentary: Written expert materials

7. Types of Witnesses
• Ordinary Witness:
• - Reports only personal perceptions
• Expert Witness:
• - Offers opinions based on specialized
knowledge

8. Probative Value of Expert
Testimony
• Depends on:
• - Judge’s knowledge
• - Expert’s qualifications
• - Logic and basis of conclusions
• - Supporting evidence

9. Forensic Chemistry Practice
• Four Stages:
• 1. Specimen Collection
• 2. Examination
• 3. Reporting
• 4. Court Appearance
• Principles: Sample sufficiency, labeling,
comparison

10. Six Golden Rules
• 1. Go slow
• 2. Be thorough
• 3. Take notes
• 4. Consult others
• 5. Use imagination wisely
• 6. Avoid complex theories

11. Common Evidence Mistakes
• - Poor packaging
• - Misidentification
• - Mishandling
• - Inadequate preservation
• - Tampering risks

12. Conclusion
• - Forensic chemistry is vital to justice.
• - Integrity of evidence and expert analysis are
key.
• - Avoiding errors ensures justice is served.