Forensic Chemistry and Toxicology PDF

Forensic Chemistry and Toxicology 2 “FORENSIC CHEMISTRY” MR.MARCSON B.REYES,RCrim,MSCJ  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Identify what are the importance of Forensic Chemistry What are the Roles of Forensic...

Forensic Chemistry and Toxicology 2 “FORENSIC CHEMISTRY” MR.MARCSON B.REYES,RCrim,MSCJ  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Identify what are the importance of Forensic Chemistry What are the Roles of Forensic Chemist? What are the equipment used in Forensic Examination? What is a Scientific Evidence?  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Few processes are more important to society than solving crimes, both to protect the public from criminals and to protect the innocent from unjust punishment. Very often, the strength of a prosecution rests on the ability of law enforcement personnel to connect the accused with the victim by matching physical evidence from the crime scene or victim with trace evidence found on or about the person accused of the crime. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry IMPORTANCE OF FORENSIC CHEMISTRY It helps in the speedy investigation of and solution to crimes. The findings of the chemical examination are valuable in convicting the guilty as well as clearing the innocent. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry WHAT ARE THE ACTIVITIES OF A CRIME LABORATORY? The primary function of the laboratory is the scientific examination of evidence in cases criminal in nature.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry ROLES OF THE FORENSIC CHEMIST IN THE SCIENTIFIC CRIMINAL INVESTIGATION: The forensic chemist plays an important role in the scientific criminal investigation. He may be called upon to aid an investigation in:  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry a.Determining whether or not a place/ location is a clandestine laboratory  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry b. Examination of marked bills / suspects during entrapment (extortion case)  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry c. Taking Paraffin Test  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Four stages of work of a forensic chemist: 1.Collection and reception of specimen for lab. Examination a.sufficiency of sample b.standard for comparison c. maintenance of individuality d.labeling and scaling  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 2. The actual examination of specimen 3. Communication of the result of examine 4. Court Apparatus NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry SCIENTIFIC EVIDENCE: Evidence is a proof of allegation, it is a means sanctioned by law of ascertaining in a judicial proceeding the truth respecting a matter of fact (Sec Rule 128, Revised Rules On Evidence). NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Evidence may be (a) direct; (b) indirect, which includes circumstantial evidence; and (c) hearsay.: (a)Direct evidence is that which the senses perceive. Any fact to which a witness testifies based on what he saw, heard, smelled, touched or tasted, is direct. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Circumstantial evidence is a kind of evidence which seeks to establish a conclusion by inferences from the facts proven.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Under the present law, Circumstantial evidence is sufficient for conviction if: (a)there is more than one circumstance; (b)the facts from which the inferences are derived are proven; and (c)the combination of all the circumstances is such as to produce conviction beyond reasonable doubt. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Hearsay evidence is a statement made by a witness on the authority of another and not from his own personal knowledge or observation  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 1. DYING DECLARATION, A dying declaration is called as “Leterm Mortem”, which means words said before death. “Nemo moriturus praesumitur mentire” Basis for “dying declaration” , which means “a man will not meet his maker with a lie in his mouth”.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Res gestae refers to statements made by the participants or the victims of, or the spectators to, a crime immediately before, during, or after its commission. These statements are a spontaneous reaction or utterance inspired by the excitement of the occasion, without any opportunity for the declarant to fabricate a false statement. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Forms of Scientific Evidence: Real or Autoptic evidence – is that evidence which is addressed to the senses of the court. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Testimonial Evidence – An expert may be called on the witness stand to answer all questions to propounded by both parties in the case. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Documentary evidence – Any written evidence presented by an expert in court which is relevant to the subject matter in dispute and not excluded by the Rules of Court. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry STANDARD SPECIMEN Are known specimens to compare with the questioned needed to aid in establishing a suspect’s relationship to the crime under investigation.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry SIX GOLDEN RULES IN THE PRACTICE OF FORENSIC CHEMISTRY 1.Go slowly- in able to collect all the possible evidence, it may be big, minute or perishable. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 2. Be thorough- to be careful about the details. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 3. Take notes NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 4. Use imagination NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 5. Consult Others NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 6. Avoid complicated theories  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry PRIMARY REASON WHICH MAY CONTRIBUTE TO THE DISASTER OF EVIDENCE/SPECIMEN 1.Improper packing of specimen 2.Failure of identification of specimen 3.Improper, precaution use in transmitting the specimen. 4.Lack of precautions to prevent tampering of the specimen  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry CLASSIFICATION BASED ON EVIDENCE CHEMICAL BIOLOGICAL PHYSICAL Drugs and Toxic Blood Fingerprints Substances Pigments Body Fluids Striations Solvents Tissue Glass pieces Explosives/Ballistics Plant derived materials Indentations (Tire Impressions) Gunshot Residue Saliva Tool marks Resins, fibers, soil, Urine Questioned miscellaneous trace Documents evidence Alcohol (Ethanol) Feather Plastic pieces NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Toxicology - Formed from the Greek words toxicos and logos, toxicology is the study of the symptoms, mechanisms, treatments and detection of poisoning. NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry Forensic toxicology centers on the determination of toxic substances in human tissues, organs and body fluids such as urine and blood, and the subsequent determination of the role any toxic agents may have contributed to or caused death.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry TYPES OF TOXICOLOGISTS  Descriptive Toxicologist: Performs toxicity test to evaluate the risk that exposure pose to humans  Mechanistic Toxicologist: attempts to determine how substances exert deleterious effects on living organisms.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry  Regulatory Toxicology: Determines whether or not a substance has low enough risk to justify making it available to the public. Forensic Toxicology is a subspecialty  Poison: a substance taken in sufficient quantity to cause ill health or death  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 2 classes of toxicity: acute and chronic  Acute toxicity refers to effects that occur shortly after a single exposure or small number of closely spaced exposures.  Chronic toxicity refers to delayed effects that occur after long term repeated exposures.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry HISTORY OF TOXICOLOGY ANCIENT HISTORY PREHISTORY - Poisonous plants and animals were recognized and their extracts used for hunting or in warfare. - 1500 BC – Written records indicate that hemlock, opium, arrow poisons, and certain metals were used to poison enemies or for state executions.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry POST-CLASSICAL HISTORY - 1198 – With time, people began to make the connection between exposure to a specific substance and illness or death. In 1198, Moses Maimonides wrote what may be the first collection of writings on toxicology, The Treatise on Poisons and Their Antidotes.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry - Renaissance and Age of Enlightenment – Certain fundamental toxicology concepts began to take shape. Noteworthy studies include those by Paracelsus in the 16th century and Orfila in the 19th century. - Paracelsus (16th Century) – Determined that specific chemicals were actually responsible for the toxicity of a plant or animal poison.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry MODERN HISTORY - Orfila, the founder of toxicology (19th Century) – A Spanish physician, Orfila is often referred to as the founder of toxicology. - Orfila was the first to describe a systematic correlation between the chemical and biological properties of poisons of the time.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry 20TH AND 21ST CENTURIES - Marked by great advancements in the level of understanding of toxicology. - DNA and various biochemicals that maintain body functions have been discovered.  NO. 1 Forensic Chemistry and Toxicology Forensic Chemistry and Toxicology NO. 1 Forensic Chemistry and Toxicology PR-2.1.1 “FOREMSIC CHEMISTRY” Pen & Paper/ MS Word none  NO. 1 Forensic Chemistry and Toxicology Q1.1.1-1 Question: A. Make a table that shows the classification of evidence. In each table classifies the forms of scientific evidences. B. Essay: Explain the six golden rules of Practice of Forensic Chemistry.. What is Toxicology and based on your understanding why does Toxicology is conjoined with the study of Forensic Chemistry? C. Generalization of the study:  NO. 1 Forensic Chemistry and Toxicology PR-2.1.1 For Flexible Distance Learning: Screenshot of hand written answer on bondpaper and uploaded at Edmodo Apps For Modular Distance Learning: Handwritten bondpaper and submitted at AISAT Campus Five days after the discussion. September 30, 2020  NO. 1 Forensic Chemistry and Toxicology “Don’t let what you cannot do interfere with what you can do.” – John Wooden