1 / 66

CRIME SCENES

CRIME SCENES. BASIC REASONS FOR CRIME SCENE. Reconstruction Focus on key evidence Provide immediate investigative leads Present evidence to the trier of fact. WHAT IS AT A CRIME SCENE. Evidence of events, sequence and time Evidence from the suspect

zahur
Download Presentation

CRIME SCENES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CRIME SCENES

  2. BASIC REASONS FOR CRIME SCENE • Reconstruction • Focus on key evidence • Provide immediate investigative leads • Present evidence to the trier of fact

  3. WHAT IS AT A CRIME SCENE • Evidence of events, sequence and time • Evidence from the suspect • Evidence from the scene on the suspect • Conclusive evidence • Circumstantial evidence • Interpretive evidence

  4. BASIC SCENE STEPS • Arrival issues • Stabilization issues • Scene security • Boundaries • General survey • Overview photos and sketching • Collection and preservation

  5. CRIME SCENE ARRIVAL • Safety of responding personnel • Check the medical condition of the victim • List all responding units • Prevent loss of evidence due to: • Medical aid • Suspect action • Environmental issues

  6. STABILIZE THE CRIME SCENE • Protect the perishable evidence • Exclude all uninvolved personnel • Be aware of what can damage evidence: • GSR • Heat on biological • Alcohol in the body • Isolate the participants • Effects of weather

  7. CRIME SCENE SECURITY • Use tape or guards • Purpose is to restrict access to select few • Log who enters and leaves the scene

  8. SET CRIME SCENE BOUNDARIES • Better to over estimate • Consider entry and exit • Focus on three dimensions

  9. ASSESS THE CRIME SCENE • Who needs to be notified • Supervision • Coroner • Crime lab • Sheriff/city investigators • Specialized assistance • What is critical for immediate processing • Set priorities

  10. JOBS IN PROCESSING SCENE • Photos/video • Fingerprints • Note taking • Bagger/tagger • Collector • Security

  11. GENERAL SURVEY • Limit to one or two persons • Note likely entry/exit points • Note misplaced, foreign objects • Note locations of prints/trace • Prevent contamination • Organize

  12. ORGANIZE • Designate trash areas, command center, smoking areas, equipment areas • Where is the command center, restrooms, food/drink, phones • If night is approaching, how much will be done • Order of processing

  13. SCENE DOCUMENTATION • Photography • Sketches • Note taking

  14. PHOTOGRAPHY • Orientation/overalls • Outside and inside • All directions • All four walls/ all rooms • Doors/ windows • Orientation of evidence with and without labels • Close-up

  15. ORIENTATION • LOCATION ORIENTATION • FRONT/SIDES/BACK OF BUILDING • 360 DEGREES FROM EACH SIDE OF BUILDING • 45 DEGREES FROM CORNER OF BUILDING/AREA

  16. 360 Degree Overall

  17. EVIDENCE LOCATION • AS IS • ORIENTATION/ MIDDLE/ CLOSEUP • MARKERS • ORIENTATION/MIDDLE/CLOSEUP • BEFORE AND AFTER SHOT WHENEVER SOMETHING IS MOVED IN ORDER TO SEE ITEM

  18. NOTE TAKING • Detailed • Chronological • Information such as date/times • Scene description • Items collected, date, and times • Body descriptions • Etc..

  19. CRIME SCENE SKETCHING • Definition: The rough notes and measurements one takes at a scene which shows the key physical measurements of the scene and its evidence location. • Purpose • To document relationship of evidence • To illustrate to others the crime scene • To provide an overall perspective of the scene

  20. CRIME SCENE DIAGRAMS • A diagram is the finished product that is included in the report and/or presented to an audience. • This diagram can be: • Scaled or un-scaled • Hand drawn • Computer generated (CAD) • Animated 3D video clips

  21. Basic Tools for Field Sketching • Tape measures - Preferably Inch/Metric combination • Protractor • Level and string line • Compass with sighting capability • Others such as Optical range finders. Reel measurement, Transits etc.

  22. SKETCH TYPES • Rectangular • Triangulation • XY coordinates • Angular displacement • Grids • Elevations • Cross-projections and 3 D

  23. Rectangular Coordinates • This consists of measuring the X and Y distance from two reference points or walls. • If one is going to plot the data on a computer, this is the preferred method.

  24. Triangulation • A method of measurement traditionally taught to crime scene personnel • Measurements are made directly to each of two permanent reference points • Must have a baseline measurement between the reference points.

  25. Polar or Angular Coordinates • Determine one reference point • Measure items from this reference point by angle and distance • Usually used for outdoor scenes

More Related