Crime Scene Investigation

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Crime Scene Investigation
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At the crime scene
Crime scene investigators only have one chance to
get things right!!
Successfully prosecuting suspects depend on how
evidence is handled.
Cases where improper handling of crime scene
evidence may have impacted the outcome of a
case

• JonBenet Ramsey

• O.J. Simpson

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At the Crime Scene
Protect
When a crime is called in, the first officer at
the scene should

• protect the scene to prevent the destruction of
  evidence

• anyone not involved in the investigation should
  be kept out

• no one should use the toilet, towels, phone,
  lights, etc.

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At the Crime Scene
Record
When an investigator (detective) first arrives at
the scene they do the following

• interview witnesses

• consider legal aspects (search warrants)

• take meticulous notes (these may be needed later
  in court)

• document the scene by making a rough sketch

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At the Crime Scene
Sketch

• A smooth sketch is done at the lab.

• A rough sketch is done at the crime scene.

• It includes measurements,
• Compass direction, and a legend.

• It includes a scale,
• Compass direction, and a legend.

• This is what is shown to a jury.

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At the Crime Scene
Notes

• There cannot be enough notes taken

• Notes should be in chronological order,
  detailed, and thorough

• Notes are never to be discarded

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At the Crime Scene
Search

• Depending on the location of the crime scene one
  of four search
• patterns will be used to look for evidence

Quadrant
Lane
Grid
Spiral
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At the Crime Scene
Collect
Evidence that is easily lost or fragile is
collected first.
We will talk later about how evidence is
collected such as
Blood
Ballistics
Trace Evidence
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At the Crime Scene
People found at the crime scene

• Police Officer Protect the scene.

• Medical Examiner Declare death, I.D. the body,
  determine
• cause, manner, and time of death.

• CSI Unit Collect evidence, photo crime scene,
  produce rough
• and smooth sketches.

• Detective Interview witnesses, suspects, puts
  all the pieces
• of the puzzle together.