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Forensics CHS McNiff

Forensics CHS McNiff. Vocabulary. CRIME SCENE: Any physical location in which a crime has occurred or is suspected of having occurred. PRIMARY CRIME SCENE: The original location of a crime or accident. SECONDARY CRIME SCENE: An alternate location where additional evidence may be found.

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Forensics CHS McNiff

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  1. Forensics CHS McNiff

  2. Vocabulary • CRIME SCENE: Any physical location in which a crime has occurred or is suspected of having occurred. • PRIMARY CRIME SCENE: The original location of a crime or accident. • SECONDARY CRIME SCENE: An alternate location where additional evidence may be found.

  3. Vocabulary • SUSPECT: Person thought to be capable of committing a crime. • ACCOMPLICE: Person associated with someone suspected of committing a crime. • ALIBI: Statement of where a suspect was at the time of a crime.

  4. Processing Versus Analysis • Crime scene investigations have two aspects: processing & analysis • Processing follows a series of standards steps

  5. Processing Versus Analysis • Analysis depends on: detailed observation, proper processing, making logical connections, laboratory analysis, analysis of scene patterns, and integrating all the data available • Crime scene analysis follows the steps of the Scientific method

  6. Types of Scenes • Two major categories of criminal activities having crime scenes: • property crimes (larceny, burglary, auto theft) • crimes against persons (assault, battery, sexual assault, robbery, murder)

  7. Types of Scenes • The nature of the scene will affect the way it is handled: • indoor or outdoor • public or private property

  8. Initial Actions & Scene Security • Initial actions of the first responders include: • Rendering aid and assistance to the victim • Arresting any suspects • Detaining any witnesses • Noting initial scene conditions • Securing the scene

  9. Initial Actions & Scene Security • Crime scene security is needed to preserve the integrity of the scene • Once the exigent emergency situation is resolved, subsequent actions at the scene will require a warrant • Duties and Responsibilities of the First Responders at the Crime Scene

  10. Secure & Isolate the Crime Scene • First priority is medical assistance to individuals & arresting the perpetrator. • Ropes or barricades and guards will prevent unauthorized access to the area. • Every person who enters the crime scene has the potential to destroy physical evidence.

  11. Secure & Isolate the Crime Scene • The lead investigator evaluates the scene & determines the boundaries. They do an initial walk through & develop a strategy. • All items must be documented & photographed.

  12. Steps in Scene Processing & Analysis • Scene Survey & Evidence Recognition • Scene Searches • Documentation • Evidence Collection & Preservation • Release of the Scene

  13. Scene Survey & Evidence Recognition • A scene survey is an initial walk-through to establish the type of scene, note any transient evidence, and recognize any potential physical evidence • Transient evidence is evidence that is easily destroyed or compromised

  14. Scene Survey & Evidence Recognition • Evidence recognition is the determination of which physical evidence is relevant to the case as opposed to being part of the background

  15. Types of Evidence • Transient Evidence • Odor, Temperature, Imprints and indentations, Markings, Vapor • Pattern Evidence • Direct Contact: Person/Object, Object/Object

  16. Types of Evidence • Conditional Evidence • Light, Smoke, Fire, Location, Vehicle Status, Body Status • Transfer Evidence • Classification, Physical Evidence

  17. Fundamentals for the Scene • Secure • Aid for victim, apprehension of suspect, integrity • Search • Recognition/Identification: Critical, Supporting, Superficial

  18. Systematic Search

  19. Fundamentals for the Scene • Record • Several Ways • Reconstruction • How does it all fit together

  20. Photography • The crime scene should be unaltered, unless injured people are involved, objects must not be moved until they have been photographed from all necessary angles. • If things are removed, added, or positions changed the photographs may not be admissible evidence.

  21. Photography • Photograph completely • Area where crime took place & adjacent areas

  22. Photography • Various angles if crime scene includes a body: • Take photos to show body’s location & position relative to the whole crime scene • Take close-up photos of injuries & weapons lying near the body • After the body is removed, photograph the surface underneath.

  23. Photography • When size is significant, use a ruler or other measuring scale • Digital cameras allow for enhancement & examination in fine detail. • Videotaping a scene is also becoming popular.

  24. Sketches • Once photos are taken, sketch the scene.

  25. Sketches • A rough sketch is a sketch, drawn at the crime scene, that contains an accurate depiction of the dimensions of the scene & shows the location of all objects having a bearing on the case. • All measurements are made with a tape measure • Show all items of physical evidence • Assign each item a number or letter and list it in the legend • Show a compass heading designating north

  26. Rough-sketch diagram of a crime scene. Courtesy Sirchie Finger Print Laboratories, Inc., Youngsville, N.C., www.sirchie.com.

  27. Sketches • A finished sketch is a precise rendering of the crime scene, usually drawn to scale. • Computer-aided drafting (CAD) has become the standard.

  28. Finished-sketch diagram of a crime scene. Courtesy Sirchie Finger Print Laboratories, Inc., Youngsville, N.C., www.sirchie.com.

  29. Notes • Note taking must be a constant activity throughout the processing of the crime scene. • The notes may be the only source of information to refresh memory. • Tape-recording notes at a scene can be advantageous – detailed notes can be taped much faster than they can be written.

  30. Dealing with Physical Evidence • A forensic scientist is not usually needed at the scene unless the evidence is complex or it is a major crime. • Some police agencies have trained field evidence technicians.

  31. Searching the Crime Scene • One person should supervise & coordinate. • Include all probable entry & exit points in search

  32. Searching the Crime Scene Ypsilanti Township, MI are looking for a burgundy vehicle in connection with a hit-and-run accident that critically injured an 11 year-old boy • What to search for will be determined by the particular circumstances of the crime. • Examples • Homicide • Hit-and-run • In most crimes, a search for latent fingerprints is required.

  33. Collect Physical Evidence • Physical evidence can be anything from massive objects to microscopic traces. • It may be necessary to take custody of all clothing worn by the participants in a crime. • Handle carefully & wrap separately to avoid loss of trace evidence.

  34. Collect Physical Evidence • Critical areas of the crime scene should be vacuumed & the sweepings submitted to the lab for analysis. • Mobile crime-scene vehicles carry supplies to protect the crime scene; photo, collect, & package evidence; & develop latent fingerprints.

  35. Collect Physical Evidence • The integrity of evidence is best maintained when the item is kept in its original condition as found at the crime scene. • The entire object should be sent to the lab. • If evidence is found adhering to a large structure, remove specimen with forceps or other appropriate tool.

  36. Collect Physical Evidence • In the case of a bloodstain, one may either scrape the stain off the surface, transfer the stain to a moistened swab, or cut out the area of the object containing the stain.

  37. Collect Physical Evidence • Each different item or similar items collected at different locations must be placed in separate containers. • Packaging evidence separately prevents damage through contact and prevents cross-contamination.

  38. What evidence would you collect? Mock Crime Scene: http://www.masss.gov

  39. Refrences • http://www3.sc.maricopa.edu/ajs/crime_scene_technician.htm • Bilous, Peter. Introduction to Forensic Science and Criminalistics. Washington: Eastern Washington Univesity, 5 May 2002. PPT

  40. Pics • http://www.florida-criminal-lawyer-blog.com/2009/09/property_crime_up_in_broward_c.html • http://www.citylinks.org.uk/Images/content/84/163229.jpg • Bug pic • http://1.bp.blogspot.com/_6QSuOepyXPE/SlJutRXLJII/AAAAAAAADPg/PEpeaUgkuyo/s400/lubber.JPG • http://thedebodeq.webs.com/apps/blog/show/prev?from_id=5880111 • http://www.csialliance.org/the-basic-steps-to-become-crime-scene-investigator-career/ • http://www.google.com/imgres?imgurl=http://wc1.smartdraw.com/examples/content/Examples/10_Legal/Crime_Scene_Investigation/Crime_Scene_-_Public_Restroom_ • http://www.newsday.com/long-island/suffolk/victim-s-family-asks-public-for-help-catching-killer-1.2100728 • http://emt-salary.org/emt-jobs-what-you-must-know/ • http://thisblogsuckssorry.blogspot.com/2011/03/things-id-rather-do-than-watch-prince.html • http://mmocker.com/2009/08/web-loot-hit-and-run-fail/ • Ypsilanti Township, MI are looking for a burgundy vehicle in connection with a hit-and-run accident that critically injured an 11 year-old boy

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