1. Crime Scene Investigation

2. 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

3. 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.

4. 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
take photographs
Investigators motto: “Eyes open, mouth closed, hands in pockets”

5. At the Crime Scene Photographs ▪ Do not take the place of the sketch
▪ Should include location, overall photos of the scene, evidence and close-up(items + items with a ruler)
▪ Videotaping is becoming more popular

6. 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 as they could be the only source
of information to refresh memory

7. At the Crime Scene Sketch: A rough sketch is done at the crime scene.
A smooth sketch is done at the lab.
It includes measurements,
Compass direction, and a legend.
● Measurements are always taken from 2 fixed points.
It includes a scale,
Compass direction, and a legend.
This is what is shown to a jury but the rough sketch is never discarded

8. 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
Spiral
Quadrant
Lane
Grid

9. 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:
Trace Evidence
Blood
Ballistics

10. At the Crime Scene Collect:
▪ Evidence should not be removed from its source when possible.
▪ Evidence should be packaged to prevent breakage, spoilage and contamination( individually)
▪ Evidence should be marked with the recovering officer’s initials, the location and the date.
***A chain of custody must be maintained!! It’s a list of all persons who came into possession of an item of evidence.

11. 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.