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Criminal Investigation

Criminal Investigation. Crime Scene Processing Part 10. Crime Scene. Evidence - most crimes - to identify - to convict a. Reproduce the crime - evidence collection - forgery / shoplift: no crime scene b. Prepare while enroute - observant / mental notes.

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Criminal Investigation

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  1. Criminal Investigation Crime Scene Processing Part 10

  2. Crime Scene • Evidence - most crimes - to identify - to convict a. Reproduce the crime - evidence collection - forgery / shoplift: no crime scene b. Prepare while enroute - observant / mental notes

  3. Scene, cont. (1) Check for suspect - officer protection (2) Injuries to victim - medics / pronounce dead (3) Call for assistance - additional officers / experts b. Protect scene - neighbors / officers / news / medics

  4. Scene, cont. - guided through (1) First officer - in charge until relieved (2) Building search - two officers - stay together (3) Protection methods - vehicles to block streets / alleys / etc

  5. Scene, cont. - officers at certain points - police tape (4) Information in report - necessary for court - defense attorney • Crime scene search - probative value - items of no value

  6. Search, cont. a. Basic function - thorough / legal - evidence present (1) Goal of search - crime occurred / type - when committed - identify who - how committed - suggest why (motive)

  7. Search, cont. (2) Do not search until: - photo / sketching complete - conduct walk-through / mental picture b. Photography - important role - court presentation (1) Picture / video - accurately represents - immediate / kept in roll

  8. Search, cont. (2) Equipment - instamatic - Polaroid - Press cameras (35mm) - fingerprint camera (1 x 1) - movie / videotape - specialized cameras (3) Lens / filters - wide angle / fisheye / telephoto / micro - eliminate colors

  9. Search, cont. (4) Film - black and white / color / infrared - ASA: speed of film • What to photograph - general areas - specific locations - objects of evidence a. Long-range pictures - take of locality

  10. Search, cont. - suspect’s entry / exit (1) Entry toproperty - doors / gates / etc (2) Exterior - buildings / grounds (3) Identification shots - street sign / house numbers - other identifiable structures

  11. Search, cont. b. Medium-range pictures - immediate crime scene - objects of evidence c. Close-range pictures - entire surfaces (bullet hole / chair / table / etc.) - specific (hair / fiber / blood / finger-footprint) (1) Several shots - different locations - do not disturb

  12. Search, cont. d. Instant photos - bruises / wounds - vandalism - photo array • Properly performed - most valuable aids - little expertise - become familiar - basic class

  13. Photos a. Investigative photographs - any made to record object / event - clarify a point (1) Photo laboratory - greater enhancement b. Admissibility - if investigator can testify - accurately depict - area he/she observed

  14. Photos (1) Accuracy - degree it represents appearance - form / tone / color / scale (2) Camera lens - not pickup perspective / scale / distance - supported: sketch / investigative notes - ruler / scale measurement (3) Negative - sufficient proof / refute allegations

  15. Photos c. Highest quality of evidence - depict scene precisely - as found (1) Exclusive function - no people working in scene - no police equipment d. ID of photographs - precisely identified - data noted on each shot taken

  16. Photos (1) Technical history of photo - recorded in notes - how relates - permanent part of case e. Custody - establish chain of evidence (1) Who took photos - primary / lab technician

  17. Photos (2) Who maintained the film - evidence locker - case file - locked desk (3) Who developed - police crime lab - commercial processor: mail/return receipts (4) Who maintained pictures - detective / evidence technician?

  18. Photos f. Admissibility - material / relevant / competent (1) Material - relates to the case (2) Relevant - assists or explains testimony (3) Competent - represents what it purports

  19. Photos - properly identified - follows chain of evidence • General considerations - time: an essential factor - preempt other aspects of investigation a. Cannot be moved / examined - until photographed - all angles

  20. Photos (1) Undergoes significant change - passage of time (2) Photo ASAP b. Camera positions - recorded on crime scene sketch (1) Measure distance - immoveable object - vertical line / from camera lens

  21. Photos (2) Interior scenes - depict as a whole - move in closer - specific object • Marking devices - used in the field of view a. Rulers - good method - relationship of objects

  22. Devices b. Identifying letters - A / B / C / etc. - used to describe items of evidence - letter ‘A’ next to bullet hole - shown in notes / reports c. Similar marking devices - chalk marks / string / etc. (1) Can be contested - not truly represent original scene

  23. Devices (2) Two photographs - one with marking device - one without • Types of photographs a. Victims (1) All possible angles - impossible to “over-photograph” - controlled / protected crime scene

  24. Types (2) Obtain: body part not visible - back of body - if found on back b. Witnesses - same approximate location (1) Statement from witness (2) Review at trial - help from being confused

  25. Type c. Clothing - description recorded - before moving body (1) Clothing removed - photograph where found - accurate measurements taken d. Weapons - photo where found - before moving

  26. Type (1) Unable to photo - take of general area - notes taken: allow accurate testimony e. Bloody areas - colored photos - large concentrations / small bloodspots (1) Include ruler (2nd photo) - bloody drag marks - photo completely

  27. Type (2) Photo any / all clothing - boot / shoe - ruler next to (3) Notes at time - direction blood was traveling - approximate size of spots f. Scrape / drag marks - all that show a struggle - bent grass / heel marks in sand

  28. Type (2) Important role - what actually happened - before / during / after g. Impressions - tire / shoe / boot - fabric on dirt / paint / dust - ruler: oblique lighting h. Other articles - bottles / glasses / cups / playing cards / etc.

  29. Type (1) No object should be moved - until photographed - original location • Most important element - maintaining perspective a. Viewed from particular point - relative position / size b. Any distortion

  30. Type c. Natural perspective - aiming camera at 90 degree angle - opposite wall - outdoors: fixed object d. Keep at eye level - unless tripod - viewer can see at eye level e. Overlapping segments - one direction around the room / area

  31. Type • Critical photographic requirements a. Approaches to the scene b, Surrounding areas c. Close-up: entrance / exit d. General scenario shot e. Minimum: 2 photos of body / 90 degree angles

  32. Type f. Body close-ups g. After removal of body h. Fingerprints i. Blood stains j. All items of evidence

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