Criminalistics week 1 (full)

Week 1: Lesson 1 Overview

  • Introduction and assessing crime scene evidence.

  • Importance of forensic science in enhancing safety and wellbeing in everyday life.

Forensic Science Contributions to Society

  • Determines if a crime was committed.

  • Establishes how and when a crime occurred.

  • Identifies victims and the sequence of events.

  • Enhances safety in various sectors:

    • Automobile safety

    • Fire prevention and suppression

    • Food and drug safety

    • Public place safety (e.g., amusement parks)

    • Transportation safety

  • Forensic science connects science to civil and criminal law, highlighting its importance in monitoring behavior impacting society.

  • Media portrayal often influences public perception, focusing primarily on criminal justice applications.

Understanding Scientific Method and Criminalistics

  • Importance of understanding complexities when reconciling forensic science with the law.

  • Contrasting methods of decision-making in science versus legal systems.

History and Development of Forensic Sciences

  • Emergence of methods to classify and compare physical evidence integrated with legal needs.

Media Representation of Forensic Science

  • Positive Aspects:

    • Increased public awareness.

    • Better-informed citizens.

    • Heightened scrutiny of law enforcement.

  • Negative Aspects:

    • Misperceptions about crime types and the justice system.

    • Increased fear of crime.

    • Added pressure on law enforcement agencies.

  • Recognizing that a small percentage of evidence is collected; resource limitations may lead to crime prioritization based on significance and profile.

  • Evidence mishandling occurs more frequently than recognized, particularly in specific regions.

Influential Figures in Forensic Science

  • Sir Arthur Conan Doyle:

    • Influenced public perception through "Sherlock Holmes" series, early promotion of scientific methods in crime-solving.

  • Mathieu Orfila:

    • Founder of forensic toxicology; wrote about poisons and their effects, linking forensic findings to the legal framework.

    • Emphasized the relationship between arsenic in soil and poisoning.

  • Alphonse Bertillon:

    • Developed anthropometry for personal identification; introduced systematic body measurements leading to criminal identification.

  • Francis Galton:

    • Conducted first fingerprint analysis; established classification methodologies for fingerprinting.

  • Leone Lattes:

    • Innovated methods to identify blood types from dried stains, enhancing identification techniques in serology.

  • Calvin Goddard and Albert Osborn:

    • Focused on ballistic analysis and document examination, respectively, improving investigative techniques.

  • Walter C. McCrone:

    • Renowned for advancements in microscopy and trace analysis.

  • Edmond Locard:

    • Established Locard's Principle of Exchange, highlighting evidence transfer between crime and criminal.

Crime Laboratory Services

  • Purpose: Research facilities applying forensic technology to analyze evidence from criminal cases.

  • Basic Units:

    • Physical Science Unit (chemical testing).

    • Biology Unit (DNA profiling).

    • Firearms Unit (ammo examination).

    • Document Examination Unit (authenticity analysis).

    • Photography Unit (forensic evidence documentation).

  • Optional Units:

    • Toxicology Unit (substance analysis of fluids and tissues).

    • Latent Fingerprint Unit (processing fingerprint evidence).

Role of Forensic Scientists

  • Critical in gathering, analyzing, and interpreting physical evidence.

  • Main tasks include:

    • Evidence analysis and expert testimony.

    • Training on evidence recognition, collection, and preservation.

Evidence Collection and Analysis

  • Focus on physical evidence, which serves as a link between crime, victim, and perpetrator.

  • Different types of evidence include biological samples, documents, drugs, firearms, and more.

  • Identification Process: Determines physical or chemical identity with high certainty.

  • Individualization: Assesses whether particular evidence can be traced back to a specific origin.

Testimonial Evidence

  • Relies on witness accounts or previous knowledge.

  • Types include personal and physical descriptions, influenced by various factors.

  • Reliability is key, with numerous factors affecting it, including perceptivity, emotional state, and prejudices.

  • Techniques to enhance the accuracy and objectivity of testimonies:

    • Comparisons and sketches.

    • Voice and ear identification.

    • Identification parades for suspect recognition.

Modus Operandi (MO)

  • Defines a criminal's method of operation.

  • Influenced by various factors such as psychological variables, prior experiences, and opportunity.

  • Essential for identifying patterns in criminal behavior and linking crimes.

  • Phases of MO: Planning phase (premeditation) and operational phase (execution).