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THE CASE: An individual works with the police to identify criminals. Her/his help is invaluable even when she/he hasn’t witnessed a crime. Many of the criminals shehe identifies are never caught, but the police continue to ask this individual for help. Coincidentally, the individual’s first name describes what she/he does to help the police. THE MYSTERY: What is the individual’s first name and what is her/his occupation?
THE MYSTERY:What is the individual’s first name and what is his occupation? CLUES: The individual’s name is not unusual. The individual is on the police payroll. The individual works with his hands and listens carefully to what other people have to say. The individual is a trained professional, but also draws on natural talent. The individual might share her/his name with the whole department. The individual has a 3 letter name.
Locard’s Principle In forensic science, Locard's principle holds that the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence. Dr. Edmond Locard (13 December 1877 – 4 May 1966) was a pioneer in forensic science who became known as the Sherlock Holmes of France. He formulated the basic principle of forensic science: "Every contact leaves a trace".
The Silent Witness…. "Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value."
First On The Scene Aim: How does Locard’s Principle Apply to the Crime Scene?
Ripples in a pond are like traces left at the scene of a crime, they are produced as a consequence of an action. They can be far-reaching and often misleading. The scientist must interpret them correctly for their true significance.
Locard’s Exchange Principle: The exchange of materials between two objects that come into contact with one another. Every Contact Leaves a Trace
“Every Contact Leaves a Trace.” • Sir Edmond Locard (1877-1966) • Sherlock Holmes of France • Created a very simple idea, that while obvious to us now, was (and still is) quite powerful to the science of Forensics. • Being able to find the “trace” is only limited by our abilities, knowledge, and degree of refinement of techniques & equipment.
Crime Scene Processing Protocol Great care must be taken in order not to contaminate the crime scene. Locard’s Exchange principle state that: When a person has contact with someone or something, that person always leaves something behind. It may be a hair or a skin cell, but something is there. Forensic Science: can be defined as any science as it relates to law. Because of this, any science can be a “Forensic” science.
Basics of crime scene processing: 1. INTERVIEW2. EXAMINE3. PHOTOGRAPH4. SKETCH5. PROCESS
Interview: The crime scene technician must interview the first officer at the scene or the victim to ascertain the "theory" of the case. • Examine: Examine the scene to identify possible items of evidentiary nature, identify point of entry and point of exit, and getting the general layout of the crime scene.
Photograph: Photographing the crime scene to record a pictorial view of what the scene looks like and to record items of possible evidence. Crime scene photographs are generally taken in two categories, overall views and items of evidence.
Sketch: A rough sketch is completed by the crime scene technician to demonstrate the layout of the crime scene or to identify the exact position of the deceased victim or evidence within the crime scene.
Process: The crime scene technician will process the crime scene for evidence, both physical and testimonial evidence. It is the crime scene technicians responsibility to identify, evaluate and collect physical evidence from the crime scene for further analysis by a crime laboratory.
Chain of Custody (evidence):An unbroken chain of events regarding all evidence collected. This includes the location of all evidence from the time collected until submitted in court as well as the person responsible for the evidence. 1.
Chain of Custody 1. Do not move anything 2. Take measurements in order to complete a detailed, scaled sketch. Include the scale on the drawing 3. Record the evidence you would like to see in the future. You may label any evidence with a note card or record the number if a note card is already in place. 4. Request additional photographs. 5. Be aware of EVERYTHING. Use your best skills of observation
Personnel Duties & Responsibilities • Team Leader • Assumes control at scene, conducts initial walk-through, determines search patterns, designates individuals for jobs • Photographer • Sketch Artist • Evidence Recorder & Custodian • Maintain logs & proper packaging • Specialists Forensic Anthropologist - Blood Spatter Analyst Bomb Technician - Medical Examiner - Entomologist - Odontologist - Engineer - Latent Print Examiner - Ballistics - Arson - Impression Expert
