Crime Scene Investigation

12/8/2011
Stages of Processing the
Crime Scene & Responsibilities
The following are general guidelines and will vary
depending on the seriousness and type of crime scene.
Not all procedures will be used at every scene.
Approach the Scene
• Personal safety and emergency care must come first
• Check/re-check scene for suspects or other danger
• Render first aid and request emergency services
• Strive to preserve the scene and any possible evidence
• Make others aware of evidence to minimize disruption
• Make initial observations and be prepared to take control
of the scene, especially if you will be processing the scene
• Briefly interview first responding officer or complainant
• Be alert for discarded evidence or a secondary scene
• Make pertinent notes
Secure and Protect the Scene
• Identify the boundaries of the scene and safety issues
• Establish adequate security and an entry/exit point
• Use personnel, police tape or barricades
• Start with a larger boundary and reduce as necessary
• Control and limit access to the scene to only necessary
personnel
• Keep out family members, neighbors, curious officers, etc
• Identify and document all individuals at the scene
• Victims, Witnesses, EMS, other Officers, etc
• Create a crime scene entry log
Secure and Protect the Scene -
continued
• Identify and protect transient evidence
• Body fluids or footwear impressions outside from
weather conditions
• If a victim’s body or other evidence is moved or collected
because of necessity, document it, but don’t put it back
• At the scene, do not
• Smoke, chew tobacco, eat, drink or spit
• Use the phone, toilet or touch anything before processing
• Alter anything before it’s documented and photographed
Conduct a Preliminary Survey
• Obtain additional details from the first responding officer
or the complainant
• Conduct a cautious walk-through
• Determine the extent of the search area
• Exterior, interior, specific rooms
• Evaluate search and seizure issues
• Use personal protective equipment for officer safety and
to minimize contamination issues
• Sanitize collection equipment or use single use items
Conduct a Preliminary Survey –
continued
• Determine equipment and personnel needs
• Photographic, DNA collection, latent processing, lighting
• Specialized personnel or just extra help
• Document your observations and actions
• Conditions of scene and evidence such as lights on or off,
door forced, lock broken, blood appeared wet/dry, etc
• If it catches your attention, document it
• Continue documentation as you progress through the
scene and investigation
• Photographs and diagrams supplement the notes but
they all work together
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Photograph the Scene
• Shoot scene ASAP
• As you find it before items are moved
• Overall, medium, close-up (Rule of 3) of all
evidence
• Relate items to location & condition
• Evidence both without and also
with accurate scale & identifiers
• Photography is inexpensive,
• Video can supplement still photography
Prepare a Diagram (if necessary)
• Supplements your photos
• Should Include
• Location
• Date
• Case Number
• Preparer’s name
• Compass orientation (north)
• Legend
• Method of measurement
• Baseline, triangulation, etc.
• Indicate “Reference Points”
• “Not to scale”
Conduct a Detailed Search
• Best search options are typically most time
consuming and difficult
• Choose a method that will be productive and efficient
• Strip, Double Strip or Grid, Spiral, Point to Point, etc.
• Two basic search approaches (in order):
• Thorough search of visible/accessible areas
• Cautious search of difficult/concealed areas
• Remember search warrants may be necessary
• Collect/process most transient evidence first
Process & Collect Evidence
• Photograph items PRIOR TO processing/collection
• Indicate items on your sketch & evidence log
• Maintain a “Chain of Custody” record
• Process evidence at scene or package properly for
later processing
• Prevent loss of latent impressions & cross-contamination
• Do not handle excessively after recovery
• Wear protective gear such as gloves
• Physical evidence can make or break a case
• Physical evidence doesn’t lie
• Juries like physical evidence
Conduct a Final Survey at Scene
• Review all responsibilities/ tasks of the scene
• Discuss findings with scene personnel/Officer in
charge
• Double-check documentation to avoid errors
• Account for all evidence & equipment
• Conduct a final walkthrough
• Have you given the scene the appropriate amount of
effort and attention within your time constraints?
Release the Crime Scene
• After completion of final survey
• Once released, re-entry will most likely require a
search warrant
• Release with the idea that there is only one chance to
perform job correctly and completely
• Returning at a later date can’t ensure the integrity of
the scene
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