first responder (usually a uniformed police officer): 1.medical assistance is first...
TRANSCRIPT
The Crime Scene
Errors at the crime scene in protecting, gathering, and processing evidence can
NEVER BE CORRECTED!!!
First responder (usually a uniformed police officer): 1. Medical assistance is first priority…protecting evidence is
secondary!2. Protect scene…nothing new added or altered, nothing removed.3. Detain suspects/witnesses.
Medical examiner:4. Note condition of body, estimate time of death.
Crime Scene Investigator:5. Interviews first responder, victims, witnesses6. Record details (weather, odors, light, visibility, etc)
A. Preserving and Isolating the Crime Scene
ADAPTAssess crime scene
Detain witnesses
Arrest perpetrator
Protect the scene
Take notes
B. Observing and Documenting the Scene
1. Notes; Thorough, complete, clear, legibleMeasure distances, date/time and description of everythingInclude full names and addresses of all peopleMay tape-record descriptions
2. Photographs and videotapes; Unaltered crime scene Overviews and close-ups, use rulers to show scale
3. Sketches; Give measurements, scale, relative placement of details Date and Time, reference points, all relevant names Never add/subtract details from an original sketch
C. Searching the Scene for Evidence
Anything that could carry trace evidence or anything that should not be there.
Use extreme care in identifying, packaging, and labeling each piece of evidence.
Special lighting may help show body fluids.
Four standards for admissible evidence:
(a) Legally obtained
(b) Relevant
(c) Identify the item
(d) Maintain the chain of custody
(1) INTEGRITY – sample is preserved and uncontaminated
(2) GENERL RULES – use separate containers, label each item, beginning with the most fragile (such as fingerprints, bloodstains, etc)
D. Collecting and Packaging Physical
Evidence
•Wear sterile vinyl or latex gloves•Wet items dried first•Containers sealed tightly•Biological items dried and frozen•Clothing with trace evidence, entire garment bagged•Firearms inside a wooden box and fixed in place to prevent movement •Arson evidence in airtight containers to prevent evaporation or dispersal of fumes•Adhesive tape and small vacuums pick up EVERYTHING (not just the evidence)•Tweezers, pens, uncontaminated objects to pick up evidence
Also consider…
example…CARPET SAMPLES FROM AN AREA THAT WAS AFFECTED BY FIRE AND THE SAME CARPET FROM AN AREA THAT WAS UNAFFECTED BY FIRE
Obtain controls
E. Maintaining the Chain of Custody
Written record of everyone who has had contact with the evidence from the time of collection to the time it may appear in court.
A likely sequence of events based on physical evidence and statements made by any witnesses
Reconstruction of the Crime
1. Crime scene processing, recognition, documentation, and collection.
2. Identification and Classification of evidence…goal is individualization of as much of the evidence as possible using comparison testing, evaluation, and interpretation
3. Attempt to reconstruct the crime.
4. Report and present all findings in a logical and convincing manner.