Crime scene sketching basics


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Crime scene sketching basics

  1. 1. Crime Scene Sketching Basics Tutorial
  2. 2. Introduction: <ul><li>The crime scene sketch: </li></ul><ul><li>Accurately portrays the physical facts </li></ul><ul><li>Relates the sequence of events at the scene </li></ul><ul><li>Establishes the precise location and relationship of objects and evidence at the scene </li></ul><ul><li>Creates a mental picture of the scene for those not present </li></ul><ul><li>Is a permanent record of the scene </li></ul>
  3. 3. Overview <ul><li>A crime scene sketch assists in: </li></ul><ul><li>1) Interviewing and interrogating persons </li></ul><ul><li>2) Preparing an investigative report </li></ul><ul><li>3) Presenting the case in court </li></ul><ul><li>The sketch supplements photographs, notes, plaster casts and other investigative techniques. </li></ul><ul><li>Two types of sketches </li></ul><ul><li>Rough sketch </li></ul><ul><li>Finished or scale sketch </li></ul>
  4. 4. The Rough Sketch <ul><li>The rough sketch is the first pencil-drawn outline of the scene and the location of objects and evidence within this outline. </li></ul><ul><li>Usually not drawn to scale </li></ul><ul><ul><li>Although distances are measured and indicated in the sketch </li></ul></ul><ul><li>Sketch after photographs are taken and before anything is moved. </li></ul><ul><li>Sketch as much as possible. </li></ul>
  5. 5. Sketching Materials <ul><li>Paper </li></ul><ul><li>Pencil </li></ul><ul><li>Measuring tape </li></ul><ul><li>Ruler </li></ul><ul><li>Clipboard </li></ul><ul><li>Eraser </li></ul><ul><li>Compass </li></ul>
  6. 6. Steps in Sketching the Crime Scene <ul><li>Observe and plan </li></ul><ul><li>Measure distances </li></ul><ul><li>Outline the area </li></ul><ul><li>Locate objects and evidence within the outline </li></ul><ul><li>Record details </li></ul><ul><li>Make notes </li></ul><ul><li>Identify the sketch with a legend and a scale </li></ul>
  7. 7. Measure and Outline Area <ul><li>A steel tape is best </li></ul><ul><li>It doesn’t stretch </li></ul><ul><li>Use conventional units of measurement </li></ul><ul><ul><li>Inches </li></ul></ul><ul><ul><li>Feet </li></ul></ul><ul><ul><li>Centimeters </li></ul></ul><ul><ul><li>Meters </li></ul></ul>
  8. 8. Measure and Outline Area <ul><li>North should be at the top of the paper. </li></ul><ul><li>Determine Scale </li></ul><ul><li>Take the longest measurement at the scene and divide it by the longest measurement of the paper used for sketching. </li></ul><ul><li>½”= 1’small rooms </li></ul><ul><li>¼”= 1’large rooms </li></ul><ul><li>1/8”= 1’very large rooms </li></ul><ul><li>½”= 10’large buildings </li></ul><ul><li>1/8”= 10’large land area </li></ul>
  9. 9. Measure and Outline Area <ul><li>Measure from fixed locations </li></ul><ul><ul><li>Walls </li></ul></ul><ul><ul><li>Trees </li></ul></ul><ul><ul><li>Telephone poles </li></ul></ul><ul><ul><li>Corners </li></ul></ul><ul><ul><li>Curbs </li></ul></ul><ul><ul><li>Outlets </li></ul></ul><ul><ul><li>Any Immovable Object </li></ul></ul>
  10. 10. Plotting Objects & Evidence <ul><li>Plotting methods are used to locate objects and evidence on the sketch. </li></ul><ul><li>They include the use of: </li></ul><ul><ul><li>Rectangular coordinates </li></ul></ul><ul><ul><li>A baseline </li></ul></ul><ul><ul><li>Triangulation </li></ul></ul><ul><ul><li>Compass points. </li></ul></ul>
  11. 11. Rectangular Coordinates <ul><li>Uses two adjacent walls as fixed points as distances are measured at right angles </li></ul>
  12. 12. Baseline Method <ul><li>Run a baseline from one fixed point to another, from which measurements are taken at right angles. </li></ul>
  13. 13. Triangulation <ul><li>Uses straight-line measurements from two fixed objects to the evidence to create a triangle with evidence in the angle formed by two straight lines. </li></ul>
  14. 14. Compass Point Method <ul><li>Uses a protractor to measure the angle formed by two lines </li></ul>
  15. 15. Cross-Projection Method <ul><li>Presents floors and walls as the were on one surface. </li></ul>
  16. 16. Make a Legend <ul><li>Contains: </li></ul><ul><ul><li>Case number </li></ul></ul><ul><ul><li>Type of crime </li></ul></ul><ul><ul><li>Investigator </li></ul></ul><ul><ul><li>Persons assisting </li></ul></ul><ul><ul><li>Direction of North </li></ul></ul><ul><ul><li>Identifying information in sketch -Key </li></ul></ul><ul><ul><li>Scale </li></ul></ul>
  17. 17. Sample Sketch
  18. 18. The Assignment <ul><li>Now it’s your turn! In a moment you will visit a 360 0 Virtual Crime Scene. </li></ul><ul><li>You will need to complete a rough sketch and finished sketch of all rooms at the crime scene. </li></ul><ul><li>Be sure to explore all rooms floor to ceiling and wall to wall. </li></ul><ul><li>Remember to include a legend </li></ul><ul><li>I will provide you with the necessary measurements to include in your sketches. </li></ul>
  19. 19. Sketches Should Include: <ul><li>Bodies </li></ul><ul><li>Furniture (tables, chairs, desks, lamps, couches, etc.) </li></ul><ul><li>Key objects on or near furniture </li></ul><ul><li>Windows, doors </li></ul><ul><li>Weapons or other evidence (bullets, broken glass, drugs, etc.) </li></ul><ul><li>Blood spatter or prints </li></ul>
  20. 20. Important Measurements <ul><li>Kitchen 11 X 13 </li></ul><ul><li>Living Room 13 X 16 </li></ul><ul><li>Study 10 X 12 </li></ul><ul><li>Hall 8 X 8 </li></ul><ul><li>Conservatory 10 X 11 </li></ul><ul><li>Bloody Knife 1’6” from wall </li></ul><ul><li>Kitchen victim – right foot 2’ from wall, left foot 4’ from wall, head touching wall </li></ul><ul><li>Living room victim – head 1’6” from stairs, left heel 3’ from cupboard, right knee 4’6” from desk </li></ul><ul><li>Hammer 1’ from chair leg and 3’ from adjacent wall </li></ul><ul><li>Car keys 2’2” from doorway and 3’10” from chair leg </li></ul><ul><li>Shoe 2’5” from conservatory door </li></ul>
  21. 21. The Crime Scene <ul><li>Visit the virtual crime scene below and begin sketching! </li></ul><ul><li> </li></ul><ul><li>You will need to scan your completed sketches, save as a PDF file, and email to me or upload to Moodle. </li></ul>