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Forensic Science

2. Chapter 10. CRC Press: Forensic Science, James and Nordby, 2nd Edition. Chapter 10. Crime Scene InvestigationChapter Author: Marilyn T. MillerPresentation created by Greg Galardi, Peru, Nebraska. 3. Chapter 10. CRC Press: Forensic Science, James and Nordby, 2nd Edition. Crime Scene Inves

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Forensic Science

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    1. Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition 1# Forensic Science An Introduction to Scientific and Investigative Techniques Stuart H. James and Jon J. Nordby Page 1Page 1

    2. 2 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Chapter 10 Crime Scene Investigation Chapter Author: Marilyn T. Miller Presentation created by Greg Galardi, Peru, Nebraska Page 167Page 167

    3. 3 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Investigation Crime scene investigation is the beginning point for obtaining evidence which will be used by the crime scene investigator and the forensic expert. It is critical a thorough crime scene investigation be completed. Page 167Page 167

    4. 4 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Defining a Crime Scene Crime scenes are inconsistent- each one presents the investigator a new challenge Crime scenes may be classified by the original location of the crime, or as the primary crime scene Subsequent locations or scenes are known as secondary crime scenes P 167P 167

    5. 5 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Defining a Crime Scene Crime scenes may also be classified according to size: Macroscopic- comprised of many crime scenes, such as a gunshot and victim’s body dumped in a field Microscopic – trace evidence found on body, gunshot residue, or tire tread marks P 167P 167

    6. 6 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Defining a Crime Scene Crime scenes may also be classified by: Type of crime: Homicide, robbery, burglary, sexual assault By organization or disorganization of scene Physical location – indoor, outdoor, vehicle Criminal behavior associated with scene- passive or active P 168P 168

    7. 7 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Use of and Information from Physical Evidence in Criminal Investigations Objective of crime scene investigation is to recognize, collect, interpret, and reconstruct all relevant physical evidence at scene Forensic laboratory examines all evidence submitted to assist in solving crime P 168P 168

    8. 8 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Types of Information Obtained from Examination of Physical Evidence Corpus Delicti- determination of essential elements of investigation- physical evidence, patterns of evidence, and laboratory examinations of evidence Modus Operandi – certain behavior associated with a criminal- normally they repeat their behavior P 168P 168

    9. 9 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Types of Information Obtained from Examination of Physical Evidence Linkage of persons, scenes and objects- Locard's Exchange Principle- when two objects come into contact, an exchange of matter will take place Linking suspects to victims and crime scenes is most important factor in crime scene investigation P 168P 168

    10. 10 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Types of Information Obtained from Examination of Physical Evidence Proving or disproving witness statements: Credibility is important issue for witnesses, victims and suspects Presence of physical evidence assists in establishing credibility when used as part of a statement Crime scene patterned evidence, such as fingerprints, bloodstains, etc all assist in establishing credibility - P 168-9P 168-9

    11. 11 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Types of Information Obtained from Examination of Physical Evidence Identification of suspects – recognition, identification, individualization, and reconstruction are all steps in successful forensic examination AFIS and CODIS are examples of methods used to determine individualization P 169P 169

    12. 12 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Types of Information Obtained from Examination of Physical Evidence Identification of unknown substances- drugs, poisons, bacteria, and anthrax Reconstruction of a Crime – final step in forensic examination process Providing Investigative leads – physical evidence may provide indirect leads, some is individualizing, other is not P 169P 169

    13. 13 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Science and Crime Scene Investigations Four steps in crime scene investigation: Recognition - Scene survey, documentation and collection Identification - comparison testing Individualization – Evaluation and Interpretations Reconstruction – Reporting and Presentation P 169P 169

    14. 14 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition General Crime Scene Procedures Four components of crime scene management: Information management Manpower management Technology management Logistics management Deficiencies, negligence or overemphasis of any one of these will imperil crime scene investigation. P 170P 170

    15. 15 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Investigation Models Five types of investigation models Traditional Crime Scene Technician Major Crime Squad Lab Crime Scientist Collaborative Team P 170P 170

    16. 16 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition First Responders First responder to crime scene has duties of: Assist the victim Search for and arrest suspect if present Detain all witnesses Protect and secure crime scene Note and communicate information from scene to investigators P 171P 171

    17. 17 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Securing the Crime Scene Locard’s principle- basis for linking physical evidence at scene to victim, suspect, or witness Multilevel crime scene security: Level 1 – general public restricted Level 2 – restricted to official business Level 3 – target area – highest security Occasionally, a command center may be set up P 171P 171

    18. 18 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Survey Upon arrival, the investigator will: Survey or walk through the scene, including: Use instant photography, make metal and written notes to document information Note conditions of scene Be aware of weather Note points of entry and exit Record initial observation of who, what when, why, and how Assess scene for further personnel or equipment needs P 173P 173

    19. 19 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Taking notes at the scene Effective notes are needed at any crime scene. They should include: Date and time of notification and information received Arrival information Scene description Victim description Crime scene team members P 173P 173

    20. 20 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Videotaping the Crime Scene Videotaping has become widespread due to availability of videotaping equipment Keys to videotaping Don’t show members of crime scene investigation team Don’t use audio Does not act as a substitute for other crime scene measurements, work, etc P 174P 174

    21. 21 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Videotaping the Crime Scene To videotape scene: Introduce video, date, time, location, videographer, and incident or call number Start with scene surroundings Provide general orientation of scene Get view from four compass points Make smooth movements, use a tripod, and additional lighting as needed Secure original, unaltered copy for evidence P 174P 174

    22. 22 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Photographing the Crime Scene Purpose of still photography is to provide a true and accurate pictorial record of crime scene. Guidelines include taking photos of crime scene: On an overall basis – include surroundings Midrange- use a stepwise progression Close-up- take pictures of evidence All- record pictures in log, be aware of reflective surfaces, take a picture when in doubt P 175P 175

    23. 23 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Items Necessary for Photographing Crime Scene 35 mm camera with normal, wide and close up lenses ( Digital cameras over 6 megapixels- if allowed by jurisdiction) Electronic flash with cord Tripod Film/recording media Label materials Scales, rulers Flashlights Extra batteries Log sheets P 175P 175

    24. 24 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene sketching Two types of crime scene sketches- Rough sketch Finished sketch Two types of crime scene perspectives Overhead or bird’s eye view Elevation or side view sketch P 176P 176

    25. 25 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Sketching Three techniques to measure crime scene: Triangulation Base line Polar coordinates All three methods use two starting fixed points and all measurements are related to those two points P 176P 176

    26. 26 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene sketching Crime scene sketches require: Title or caption Legend of abbreviations Symbols Numbers or letters used Compass designation Scale, if drawn to scale Documentation block with case number, offense type, victim names, location, date and time, and sketcher’s name P 176-7P 176-7

    27. 27 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Digital Imaging at the Crime Scene Powerful new tools Many law enforcement agencies and courts have not established protocols (evidentiary admissibility questions) Best used as a supplemental tool Written policies must be in place to use digital imaging p 177 p 177

    28. 28 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Searches Preliminary search is an initial search for physical evidence present Notes obvious pieces of evidence Document and complete more thorough search Patterns of search include: Link Line Grid Zone Wheel Spiral p177 p177

    29. 29 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Collection and Preservation of Physical Evidence No set order for evidence collection, but items taken into consideration: Transient or fragile evidence collected first All evidence should be placed in appropriate container Tamper resistant evidence tape should be used Each evidentiary item should be placed in separate appropriate container and labeled P 179P 179

    30. 30 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Reconstruction Crime scene reconstruction is the process of determining or eliminating events that occurred at the crime scene by analysis of crime scene appearance, location and positions of physical evidence, and forensic examination of evidence P 179-180P 179-180

    31. 31 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Crime Scene Reconstruction Includes: Scientific crime scene investigation Laboratory testing of physical evidence Systematic study of related case information Logical formulation of a theory P 180P 180

    32. 32 Chapter 10 CRC Press: Forensic Science, James and Nordby, 2nd Edition Stages of Reconstruction Data Collection Conjecture Hypothesis formulation Testing Theory formulation Reconstructions are only as good as the information provided! P 180-1P 180-1

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