Unit 2: The Crime Scene
Evidence
Physical evidence: Any object that can establish that a crime has or has not committed
a. links crime to ____________________
b. links crime to ____________________
c. must be found or recorded at the _______________ ________________and preserved
carefully for examination.
Trace evidence: evidence that is created when two objects come in contact
Circumstantial evidence: evidence in a trial which is not directly from an eyewitness or participant
and requires some reasoning to prove a fact.
Seven “S’s” of Crime Scene Analysis
1. Securing the Scene
a. Responsibility of ______________________
b. Notes persons at the scene and leaving the scene, persons needing medical help and if
hazardous materials are present.
c. Arrests the perpetrator if present
d. Records ______________________of witnesses or information provided.
e. Authorized or essential personnel permitted at the crime scene includes:
i.
ii.
iii.
Is the victim’s family considered authorized to be in the area of the secured scene?
d. Identifies all persons at the scene and conducts ________________________. Logs
_______________and ________________of all who enter or exit.
e. Every person can affect the crime scene by _______________________.
No one should ________, move, or alter anything at the scene. No smoking, drinking, eating,
littering should be done. Why?
What are the duties of the lead investigator?
2. Separate the Witnesses
a. get each person’s account of the story separately.
b. Suggested questions to ask:
3. Scan the Scene
a. primary crime scene:
b. secondary crime scene:
Determine what photographs should be taken.
4. Seeing the Scene
Notes
What information should be included in an investigator or first responder’s notes about the
scene?
Why should detailed notes be written at the scene?
What is an advantage and disadvantage of audio or video recording at the scene?
Photography
a. Photographs should be taken with __________________ _______________ and/or
markers.
b. Triangulation of stationary objects should be included as _________________
____________.
c. Objects should be photographed at angles and both ________ ______ and far away photos
taken.
d. Bodies should be photographed in their _______________position and from multiple angles.
Space underneath should be photographed when the body is removed.
e. Film versus digital photography:
What are the pros and cons of using film? Digital?
5. Sketching the Scene
a. What information should be included in a sketch of the crime scene?
6. Search for Evidence
a. must be ____________, _________________ and ____________________
b. must be done immediately to eliminate _____________________________
c. search pattern depends on location and size of the area as well as actions of the suspect and
victim.
Strip/Line search:
Spiral search:
Wheel/ray search:
Quadrant/zone search:
7. Securing the Scene and Collecting Evidence
a. Everything is bagged and tagged ____________.
b. Use latex gloves and forceps (tweezers) to collect evidence. Never handle evidence with your
bare hands.
c. Evidence can range from minute ___________to massive objects.
Examples of evidence:
d. Time is ________________. Forensic value decreases with every tick of the clock. Exposure
to environmental elements such as cold, rain, extreme heat, etc. can alter the state of the
evidence. Bodies begin decomposing immediately after death. Buried bodies can make
collecting evidence very difficult.
e. Do not ________ _____________evidence by placing different samples in the same
container.
f. Clean equipment after use.
g. Keep evidence in its original condition to maintain integrity.
h. Assume that all body fluids are _____________________.
i. Change gloves frequently.
j. Use masks, gloves and gowns.
k. Follow chain of custody exactly.
l. Do not use ordinary mailing envelopes because fine powders and fibers can lead out. Use
folded paper to create a container if needed.
Examples of evidence containers:
What information should be on the label and paperwork accompanying an evidence sample?
What is chain of custody?
Why is maintaining a chain of custody important?
List some standard reference samples and their origin.
Why are standard samples important?
Legally Speaking
OSHA (Occupational Safety and Health Administration):
4th Amendment:
Mincey v. Arizona:
Michigan v. Tyler:
Lessons learned: