Crime Scene Protocols
- 1. Crime Scene Protocols Crime Scene Investigation Collection of Evidence
- 2. Crime Scene Investigation techniques and protocols vary by agency and region basic overlying procedures remain the same once scene is secured
- 3. Crime Scene Investigation INTERVIEW EXAMINE PHOTOGRAPH SKETCH PROCESS
- 4. INTERVIEW The lead investigator must interview the first officer at the scene or the victim to ascertain the "theory" of the case. Basically what allegedly happened, what crime took place, and how was the crime committed. This information may not be factual information but it will give the investigator a base from which to start.
- 5. EXAMINE Walk through to ascertain if the "theory" of the case is substantiated by what the investigator observes. Examine the scene to identify possible items of evidentiary nature, identify point of entry and point of exit, and get the general layout of the crime scene.
- 6. PHOTOGRAPH Photographing the crime scene records a pictorial view of what the scene looks like and records items of possible evidence. Crime scene photographs are generally taken in two categories, overall views and items of evidence.
- 7. SKETCH A rough sketch is completed by the investigator to demonstrate the layout of the crime scene or to identify the exact position of the deceased victim or evidence within the crime scene. A finished sketch may be used when presenting evidence. Many CAD tools available.
- 8. PROCESS The investigator will process the crime scene for evidence, both physical and testimonial evidence. It is the investigator’s responsibility to identify, evaluate and collect physical evidence from the crime scene for further analysis by a crime laboratory.
- 9. OVERVIEW All steps are actually intermingled with each other step. If the "theory" of the case dictates that the intruder forcibly entered the residence through a window investigator needs to examine the window area for footwear patterns, toolmarks, trace evidence and latent finger prints if found, investigator needs to photograph location and complete a sketch showing the exact location of the evidence This intermingling of steps in the protocol will continue throughout the processing. Of course interwoven throughout these five steps is the recording of the crime scene by photographs, sketches, and field notes.
- 10. Secure and Isolate Scene preserve and protect area as much as possible priority procedures for first officer on scene obtain medical assistance for individuals in need arrest of perpetrator if present exclude unauthorized personnel from scene
- 11. Record the Scene proves useful during subsequent investigation required for presentation at trial document the condition of crime site delineate the location of physical evidence
- 12. Record the Scene photography scene must be unaltered objects photographed from all necessary angles actual scene & adjacent areas scale included for reference may also use video
- 13. Record the Scene photography may include specialized techniques and equipment needed to visualize evidence that is unseen with the naked eye
- 14. Record the Scene notes must be a constant activity during processing include detailed description of items of physical evidence with time of discovery and who collected how and by whom it was packaged and marked disposition after collection
- 15. Search for Evidence depends on locale and size of scene number of investigators aiding search presumed activities of the perpetrator
- 16. Search for Evidence systematic patterns spiral
- 17. Search for Evidence systematic patterns parallel
- 18. Search for Evidence systematic patterns grid
- 19. Search for Evidence systematic patterns quadrant or zone
- 20. Collection of Evidence from massive items to microscopic traces obvious items clothing and fingernail scrapings from involved peoples vacuuming of critical areas items from body of any deceased victims
- 21. Collection of 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
- 22. Collection of Evidence chain of custody every person who handled or examined the evidence must be accounted for failure to substantiate chain of custody may lead to questions regarding authenticity integrity examination conclusions
- 23. Collection of Evidence obtain standard/reference samples for comparison DNA samples from involved individuals hair and/or clothing glass, soil, paint etc. obtain substrate controls