1. Forensic Science
Crime Scene Investigation
Part II – The Investigation Team
& Collecting Evidence

2. Crime Scene Team
A group of professional investigators, each trained in a variety of special disciplines
Team Members:
First police officer on the scene
Medics (if necessary)
Investigator (s)
Medical examiner (if necessary)
Photographer &/or field evidence technician
Lab experts

3. Crime Scene Team Lab experts: Pathologist Serologist DNA expert
Toxicologist
Forensic odontologist
Forensic psychologist
Forensic anthropologist
Forensic entomologist
Firearm examiner
Bomb & arson expert
Document & handwriting expert
Fingerprint expert

4. Investigators
“ The wise forensic investigator will always remember that he must bring all of his life experiences and logic to find the truth. This means common sense, informed intuition, and the courage to see things as they are. Then he must speak honestly about what it adds up to.”
- Dr. Henry Lee
Chief Emeritus for Scientific Services and the former Commissioner of Public Safety for the state of Connecticut

5. First Officer at the Scene
A Assess the crime scene
D Detain the witness
A Arrest the perpetrator
P Protect the crime scene
T Take notes

6. Initial Response/ Prioritization of Efforts
Arriving at the Scene:
Initial Response/ Prioritization of Efforts
Initial response and receipt of information
Safety precautions
Emergency care
Secure and control persons at the scene
Establish and preserve scene boundaries
Transfer control of the scene to the investigator (s) in charge
Document actions and observations at the scene

7. Preliminary documentation & Evaluation of the Scene
Conduct scene assessment
Conduct scene “Walk-Through” and initial documentation

8. Processing the Scene Determine team composition
Ensure contamination control
Document the scene
Prioritize collection of evidence
Collect, preserve, inventory, package, transport, and submit evidence

9. Completing and Recording the Crime Scene Investigation
Establish crime scene debriefing team
Perform final survey of the crime scene
Documentation of the crime scene

10. Eye Witness “Perception is reality.”
As a result, an eye witness may not be the best source of crime scene information.
A police composite may be developed from the witness testimony by a computer program or forensic artist.
Faces Composite Program by InterQuest

11. A TRUE EYEWITNESS Crazy Criminal
As a female shopper exited a New York convenience store, a man grabbed her purse and ran. The clerk called 911 immediately and the woman was able to give them a detailed description of the snatcher. Within minutes, the police had apprehended him. They put him in the car and drove back to the store. The thief was then taken out of the car and told to stand there for a positive ID. With that he replied, “Yes, Officer. . That’s her. That’s the lady I stole the purse from.”

12. Crime Scene Search Patterns
Spiral
Grid
Start at the center and work your way outwards
Work East-West and then North-South

13. Crime Scene Search Patterns
Strip or Line
Quadrant or Zone
Walk North/South line by line (almost like cutting grass)
Section scene off into 4 pieces and then into smaller 4 pieces

14. Crime Scene Sketches c A. Couch/sofa B. Female body C. Knife
Date: August 14, Criminalist: Ann Wilson
Time: 11:35 Location: Rockledge Dr
St. Louis, Mo.
A. Couch/sofa
B. Female body
C. Knife
D. Over turned Lamp
E. Chairs
F. Table
G. Fireplace E c D G A E E F E

15. Outdoor Crime Scene Mapping
Azimuth--uses a compass beam to determine the location of each piece of evidence
Triangulation--uses two points at the crime scene to map each piece of evidence
Coordinate or grid--divides the crime scene into squares for mapping.
Suspended Polar Coordinate --for use in mapping evidence in a hole
Baseline--set a north/south line and measures each piece of evidence from this line.

16. AZIMUTH
Determines:
Direction
Distance
Elevation

17. TRIANGULATION
Measure from A to B and then to the evidence in a triangular shape.

18. Set a north/south line from a datum point established by a GPS.
Coordinate or Grid Mapping
Set a north/south line from a datum point established by a GPS.
Measure and map the location of each piece of evidence. Then collect evidence and place in containers by grid.
Make it a perfect square (4 x 4) by shooting the hypotenuse and setting in stakes every foot or meter.

19. Baseline Mapping
Set a north/south line from the furthest most points of the crime scene. Then measure each piece of evidence from that baseline. Evidence will need a numerical measurement where the piece begins, ends and in the middle.
Evidence
Baseline

20. Suspended Polar Coordinate
Measure and map each layer of evidence as you move down the hole. Use the compass readings from the top to measure degrees and a tank dipping line to measure depth.

21. MAPPING TECHNOLOGY
The latest technology includes this Nikon Tsunami with computer. The exact location of all crime evidence can be determined and directly loaded into a computer to produce a crime scene map.
Cost = $35,000 for the set.

22. Physical Evidence

23. Physical Evidence
Transient Evidence--temporary; easily changed or lost; usually observed by the first officer at the scene
Odor--putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke
Temperature--of room, car hood, coffee, water in a bathtub; cadaver
Imprints and indentations--footprints; teeth marks in perishable foods; tire marks on certain surfaces
Markings – tool marks,

24. There are several ways (at least 7) of classifying evidence.
Physical Evidence
Pattern or Transfer Evidence--produced by direct contact between a person and an object or between two objects.
There are several ways (at least 7) of classifying evidence.
In this class, we will use:
Biological
Chemical
Physical
Miscellaneous

25. Physical Evidence (cont’d)
Conditional Evidence --produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances within a particular event.
Light--headlight; lighting conditions
Smoke--color, direction of travel, density, odor
Fire--color and direction of the flames, speed of spread, temperature and condition of fire

26. Conditional Evidence (cont’d)
Location--of injuries or wounds; of bloodstains; of the victims vehicle; of weapons or cartridge cases; of broken glass, etc.
Vehicles--doors locked or unlocked, windows opened or closed; radio off or on (station); odometer mileage
Body--position; types of wounds; rigor, livor and algor mortis
Scene--condition of furniture, doors and windows; any disturbance or signs of a struggle.

27. Evidence Characteristics
Class -- common to a group of objects or persons
Individual -- can be identified with a particular person or source.
ABO Blood Typing
Blood DNA Typing

28. Blood Semen Saliva Sweat/Tears Hair Bone Tissues Urine Feces
Biological Evidence
Blood
Semen
Saliva
Sweat/Tears
Hair
Bone
Tissues
Urine
Feces
Animal Material
Insects
Bacterial/Fungal

30. Fibers Paper Glass Ink Soil Cosmetics Gunpowder Paint Metal Plastic
Chemical Evidence
Fibers
Glass
Soil
Gunpowder
Metal
Mineral
Narcotics
Drugs
Paper
Ink
Cosmetics
Paint
Plastic
Lubricants
Fertilizer

31. Physical (Impression) Evidence
Fingerprints
Footprints
Shoe prints
Handwriting
Firearms
Printing
Number restoration
Tire marks
Tool marks
Typewriting

32. Miscellaneous Evidence
Laundry marks
Voice analysis
Polygraph
Photography
Stress evaluation
Pyscholinguistic analysis
Vehicle identification

33. Cadaver Dogs
Dogs with a sense of smell 100 times better than humans can sometimes find what would be overlooked. They are specially trained to locate injured, lost and/or deceased individuals. They are trained as air scent dogs or article (cloth) scent dogs.

34. Cadaver Dogs
Dogs are trained to locate human body fluids including blood, hair, teeth, urine, and semen. The dog on the left in a training exercise is trying to locate clothing with blood.

35. Cadaver Dogs
Looking at a crime scene, humans would probably miss something as small as this tooth. The dog found it within minutes of searching the scene.