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The Crime Scene

The Crime Scene. “Oh, how simple it would have all been had I been here before they came here like a herd of buffalo and wallowed all over it.” - A. Conan Doyle The Boscombe Valley Mystery. At the Crime Scene. Actual Forensic science begins at the crime scene

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The Crime Scene

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  1. The Crime Scene “Oh, how simple it would have all been had I been here before they came here like a herd of buffalo and wallowed all over it.” - A. Conan Doyle The Boscombe Valley Mystery

  2. At the Crime Scene • Actual Forensic science begins at the crime scene • The crime scene will always provide useful information that must be carefully, systematically, scientifically, and legally collected. • Crime scene investigators gather important information at the crime scene that must later be used to reconstruct the sequence of events that occurred. - This is referred to as the Modus Operandi (MO). - The motive for the crime or the characteristic method of the criminal. • A forensic scientist must carefully analyze the crime scene to learn what happened, gather evidence, identify suspects, and convict those responsible for the act. • Errors at the crime scene in protecting, gathering, and analyzing evidence can never be made right.

  3. CRIME SCENE INVESTIGATION • Based on the scientific method and the Locard Exchange Principle, logic and forensic techniques. • Involves: • Recognition - scene survey, documentation, and collection • Identification - comparison testing • Individualization - evaluation and interpretation • Reconstruction - reporting and presenting

  4. CORPUS DELICTI“Body of the Crime” • You must prove • that a crime occurred • that the person charged with the crime was responsible for the crime • Top Reasons for Committing a Crime • Money • Revenge • Emotion—love, hate, anger • Source of Evidence • Body • Primary and/or Secondary Crime Scene • Suspect (s)

  5. CRIME SCENE TEAM • A group of professional investigators, each trained in a variety of special disciplines. • Team Members • First Police Officer on the scene • Medics (if necessary) • Investigator (s) • Medical Examiner (if necessary) • Photographer and/or Field Evidence Technician • Lab Experts

  6. Processing a Crime Scene • Isolate and secure the scene • Document the scene • Search for evidence • Collect and package evidence, maintaining the chain of custody • Submit evidence to the crime lab

  7. First Officer on the Scene • A Assess the crime scene and assist those hurt • D Detain the witness • A Arrest the perpetrator • P Protect the crime scene • T Take notes

  8. The first officer on the scene determines the nature of the crime. • The officer has the basic responsibility to help the victim (if still alive) and then make an arrest if possible. • The scene must then immediately be protected from unauthorized entrants. WHY? • Finally any suspects or witnesses must be detained. • If there has been a death, the medical examiner should note the body’s condition and the time of death (if possible). • As additional personnel arrive, crime scene tape, barricades, and strategically placed officers should be used to isolate and protect the scene. • Law enforcement officers should try to note and record as many details as possible. - ex. Weather conditions, odors, whether lights were on or off, visibility, etc…

  9. Crime Scene Survey • Walk-through • Performed by the crime scene investigator, the first officer and sometimes the lead detective. • Purpose: • Mentally prepare a reconstruction theory • Note any transient or conditional evidence that could change over time. • Note weather conditions • Note points of entry or exit, as well as paths of travel within the crime scene • Record initial observations of who, what, where, when, and how • Identify special needs within the crime scene for personnel, precautions or equipment and notify superior officers or other agencies

  10. Documenting the Scene • Investigators should examine the scene to get an overall view to find possible items of evidence, to identify points of entry and exit, to consider what may have happened, and to mentally outline how the scene should be handled. • Several methods of documentation include: 1. Notes 2. Photography 3. Videography 4. Sketches

  11. Notes • Notes force investigators to be more observant. • Notes should detail every action that the investigator takes and in the order in which the steps were taken. • Notes should include the specific measurement of the scene. • Notes should also include: • Date and time. • Description of the location. • Weather and environmental conditions. • Description of the crime, location of the evidence relative to other key points. • The names of all people involved. • Modifications that have occurred and other relevant information. • Description of the evidence including its location, the time of its discovery, and the packaging it was placed in.

  12. Photographs and Videotape • Before making any detailed examination and before touching or moving any evidence, the investigator should photograph the scene. • Photographs help the investigator and witnesses remember details, show where evidence is placed in the scene, and may help the judge and jury visualize the crime scene. • All photographs should include a ruler for scale. • All photographs taken must be documented as evidence. • Investigators should include: - Photos of scene and surroundings. - Mid-range to close-up photos with various angles of each piece of evidence. - Photos of evidence or the scene as viewed by any witnesses. • Videotaping should begin outdoors and move into the indoor scene. - Videotape should be treated as evidence and never be edited or erased.

  13. Sketches of the Crime Scene • Sketching the scene can help the investigator notice and remember details through the act of drawing. • They allow for selectivity of details within the scene. • The sketch allows measurements to be made, scale to be produced, and relative placement of all important details at the crime scene. • Sketches must include the following information: - Date and Time. - Scale. - Reference Points. - Distance measurements. - Compass. - Names of investigators, victims, and suspects. - Legend or key. • An original sketch is considered evidence and must never be changed or tampered with after completion.

  14. CRIME SCENE SKETCH Date: August 14, 2005 Criminalist: Ann Wilson Time: 11:35 am Location: 4358 Rockledge Dr, St. Louis, Mo. Would you add anything to this particular sketch to make it better?

  15. Searching the Scene for Evidence • Investigators are looking for anything that shouldn’t be there and anything that might carry trace evidence such as clothing, documents, or rugs. • How the investigator carries out the search depends on the location, the size of the area, and the complexity of the crime scene. • Search Methods: 1. Line or strip method - best in large, outdoor scenes. 2. Grid method - basically a double-line search; effective, but time- consuming. 3. Zone method - most effective in houses or buildings; teams are assigned small zones for searching. 4. Wheel or ray method - best on small, circular crime scenes. 5. Spiral method - may move inward or outward; best used where there are no physical barriers.

  16. Collecting and Packaging Evidence • One individual should be designated as the evidence collector to ensure that the evidence is collected, packaged, marked, sealed, and preserved in a consistent manner. • Each item must be placed in a separate container, sealed, and labeled. • Most fragile is collected and packaged first. • Different types of evidence require specific or special collection and packaging techniques. • The body is the property of the coroner or medical examiner. The collection of evidence on the body is done by that department. • Control samples must also be collected to compare with any evidence found at the crime scene whose source is unknown. • Most items should be packaged in a primary container and then placed inside a secondary one. These are then placed inside other containers such as paper bags, plastic bags, canisters, packets and envelopes depending on the type and size of the evidence.

  17. Chain of Custody • There must be a written record of who has had possession of the evidence at all times. • The court needs to know who has been responsible for evidence from the time it was collected to the time it may appear in court. • The evidence packaging must always show who collected the evidence, who had contact with the evidence, and under what circumstances and what, if any, changes were made. • The record of the chain of custody is often recorded on a label on the evidence packaging.

  18. CRIME SCENE RECONSTRUCTION Stages • Data collection • Hypothesis formation • Examination, testing and analysis • Determination of the significance of the evidence • Theory formulation

  19. Medical Examiner’s Responsibilities • Identify the deceased. • Establish the time and date of death. • Determine a medical cause of death - the injury or disease that resulted in the person dying. • Determine the mechanism of death - the physiological reason that the person died. • Classify the manner of death. • Natural • Accidental • Suicide • Homicide • Undetermined • Notify the next of kin. • Autopsy the deceased.

  20. Autopsy • Also known as a post-mortem examination, necropsy, or obduction. • It is a medical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present. • It is usually performed by a specialized medical doctor called a pathologist. • Autopsies are either performed for legal or medical purposes. • A forensic autopsy is carried out when the cause of death may be a criminal matter, while a clinical or academic autopsy is performed to find the medical cause of death and is used in cases of unknown or uncertain death, or for research purposes. • Autopsies can be further classified into cases where external examination suffices, and those where the body is dissected and an internal examination is conducted. • Permission from next of kin may be required for internal autopsy in some cases. • Once an internal autopsy is complete the body is reconstituted by sewing it back together.

  21. Famous Pathologists • Dr. Michael M. Baden is a renowned pathologist and was the Chief Medical Examiner in NY City and for Suffolk County. • Dr. Baden was on the panel that investigated the assassinations of president John F. Kennedy and Dr. Martin Luther King, Jr. He has been involved as an expert in forensic pathology in many cases of international interest including: • The remains of Tsar Nicholas of Russia and his family • The Claus Von Bulow murder trial • Expert witness for the defense in the O.J. Simpson trial • Re-autopsy of Medgar Evers, Civil Rights leader • Re-examination of the Lindberg Kidnapping and murder • Autopsies of the victims of TWA Flight 800 • Dr. Baden is the host of HBO’s Autopsy series and is featured on many of the crime talk shows.

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