1. INTRODUCTION Crime Scene Investigation
FORENSIC SCIENCE
INTRODUCTION
Crime Scene
Investigation

2. What does a Forensic Scientist DO???
Forensic Science
Definition: The application of scientific technology to supply accurate and objective information reflecting the events that occurred at a crime.
What does a Forensic Scientist DO???
Analyze physical evidence
Provide Expert Testimony
Provide training in the recognition, collection and preservation of physical evidence

3. Complex Reasoning In Forensic Science
Deductive (reasoning from the general to the particular) and
Inductive Reasoning (reasoning from detailed facts to general principles)
Classifying
Comparing and Contrasting
Problem Solving
Analyzing Perspectives
Constructing Support
Error Analysis
Deduction--providing the proof that the situation is true.
Induction-drawing conclusions/generalization from information; listing support for the conclusions
Classifying--putting things into groups and determining the rules for the groups
Comparing--how are things alike and how are they different
Analyzing Perspectives--opinions about an issue and different ways to look at it
Constructing support--support and limitations for a particular argument
Error Analysis--determining what’s wrong and how it can be fixed

4. The History of Forensic Science
Sherlock Holmes: a fictional character developed by Sir Arthur Conan Doyle; used a great deal of forensic detection
Mathieu Orfila: toxicology (the detection of poisons)
Alphonse Bertillon: anthropometry (personal identification through body measurements)
Francis Galton: developed 1st fingerprint identification system
Leone Lattes: determined methods of using blood type as a means of identification
Calvin Goddard: firearms examination
Albert Osborn: document examination
Edmund Locard: Developed the 1st police lab
J. Edgar Hoover: director of the FBI: Organized the 1st FBI Crime Lab in 1932

5. Locard’s Exchange Principle
Whenever 2 objects come in contact with one another, they exchange some material (dust particles, hair, dead skin cells…)
Locard strongly believed that every criminal can be connected to a crime by dust particles carried from the scene

6. Branches of Forensic Science
Physical science: Using chemistry, physics, and geology to ID and compare crime scene evidence
Biology: blood, body fluids, hairs and fibers, entomology
Pathology, psychology, odontology, any many more!

7. CORPUS DELICTI “Body of the Crime”
You must prove:
that a crime occurred
that the person charged with the crime was responsible for the crime
Top Reasons for Committing a Crime
Money
Revenge
Sex
Emotion--love, hate, anger
Source of Evidence
Body
Primary and/or Secondary Crime Scene
Suspect(s)

8. 4 Major FEDERAL Crime Labs:
FBI
Drug Enforcement Administration (DEA)
Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF)
US Postal Inspection Service
Most states also have their own, smaller crime labs

9. General Crime Lab Services and the materials each unit analyzes
Physical Science Unit: drugs, glass, paint, explosives, etc
Biology Unit: blood and other bodily fluids
Firearms Unit: ballistics, comparisons
Document Examination Unit: handwriting, typewriting, questioned documents (ransom notes, etc)
Photography Unit: record all phyhsical evidence.
Toxicology Unit: presence/absence of drugs
Latent Fingerprint Unit: fingerprints
Pathology Unit-

10. Forensic Pathology
Investigation of sudden unnatural, unexplained or violent deaths
Answer the questions:
Who is the victim?
What are the injuries, when did they occur, and how were they produced?
5 manners of death: natural, homicide, suicide, accident, undetermined
GO TO SLIDE 25…..

11. Crime Scene Team
A group of professionals 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 and/or Field Evidence Technician
Lab Experts
pathologist serologist
DNA expert toxicologist
forensic odontologist forensic anthropologist
forensic psychologist forensic entomologist
firearm examiner bomb and arson expert
document and handwriting experts fingerprint expert

12. 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

13. 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

14. 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

15. Crime Scene Search Patterns
TWO of FOUR PATTERNS
Spiral
Grid

16. Crime Scene Search Patterns
TWO of FOUR PATTERNS
Strip or Line
Quadrant or Zone

17. Crime Scene Sketch c A. Couch/sofa B. Female body C. Knife
Date: August 14, Criminalist: Ann Wilson
Time: 11: 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 E F E

18. Crime Scene Mapping (outdoors)
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.

19. AZIMUTH
Determines:
Direction
Distance
Elevation

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

21. 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.

22. 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

23. 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.

24. 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.

25. 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

26. Physical Evidence (cont)
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

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

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

29. Physical (impression)
Fingerprints
Footprints
Shoe prints
Handwriting
Firearms
Printing
Number restoration
Tire marks
Tool marks
Typewriting

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

31. Physical Evidence (cont)
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

32. Conditional Evidence (cont.)
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.

33. 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

34. Medical Examiner vs the Coroner
A medical examiner is a medical doctor, usually a pathologist and is appointed by the governing body of the area. There are 7 medical examiners in the state of Missouri and 400 forensic pathologists throughout the U.S.
A coroner is an elected official who usually has no special medical training. In four states the coroner is a medical doctor.

35. Medical Examiner’s Responsibilities
Identify the deceased
Establish the time and date of death
Determine a medical cause of death--the injury or disease that resulted in the person dying
Determine the mechanism of death--the physiological reason that the person died
Classify the manner of death
Natural
Accidental
Suicide
Homicide
Undetermined
Notify the next of kin

36. THE BODY Rigor Mortis Temperature Stiffness Time Since
of body of body Death
Warm
Cold
Not stiff
Stiff
Not dead more than 3 hrs
Dead between 3 and 8 hrs
Dead 8 to 36 hours
Dead more than 36 hours

37. THE BODY Livor Mortis
Livor mortis is the settling of the blood, causing the skin to change colors.
Lividity indicates the position of the body after death. When lividity becomes fixed, then the distribution of the lividity pattern will not change even if the body’s position is altered.
Lividity usually becomes fixed between 10 and 15 hours after death.

38. THE BODY Algor Mortis Algor mortis is body temperature.
Average human body temperature: 98.6 F (37 C)

39. Time Frame of Death Condition Appearance
Periphery blood drying 30 min to 2 hrs
Blue-green discoloration of skin
Right and left area of abdomen 24 hours
Entire abdomen 36 hours
Bloating to 48 hours
Skin slippage 4 to7 days
Absence of smell from bones more than 1 year

40. Time Frame of Death Eyeball Changes
Condition Appearance
Cornea drying (eyes open) minutes
Cornea drying (eyes closed) 2 hours
Corneal cloudiness (eyes open) less than 2 hours
Corneal cloudiness (eyes closed) 12 to 24 hours
Eyeball collapse more than 24 hrs

41. THEREFORE,
One can die of a massive hemorrhage (the mechanism of death) due to a fall (cause of death) as a result of being pushed (homicide), jumping (suicide), falling (accident), or not being able to tell which (undetermined). All of which are manners of death.

42. CRIME What Happened? Why Did It Happened? Who Did It? Crime Scene
Evidence Collection
Witness, Suspect and
Motive Development
Investigative Stage
Profiling
Means
Motive
Opportunity
Identification
and Arrest of
Suspect + =
Post Scene
Evidence Processing
Cause, manner, time
of death

43. Forensic Investigations
Include some or all of these seven major activities
Recognition--ability to distinguish important evidence from unrelated material
Pattern recognition
Physical property observation
Information analysis
Field-testing
Preservation--collection and proper preservation of evidence

44. Investigations (cont)
Identification--use of scientific testing
Physical properties
Chemical properties
Morphological (structural) properties
Biological properties
Immunological properties
Comparison--class characteristics are measured against those of know standards or controls; If all measurements are equal, then the two samples are considered to have come from the same source or origin.

45. Investigations (cont.)
Individualization--demonstrating that the sample is unique, even among members of the same class.
Interpretation--gives meaning to all the information
Reconstruction--reconstructs the case events
Inductive and deductive logic
Statistical data
Pattern analysis
Results of laboratory analysis
Lee, Dr. Henry. Famous Crimes. Southington:Strong Books, 2001

46. Just A Thought
It’s not what you know that hurts you, its what you think you know and it’s not so Mark Twain
How does this apply to forensic science and crime investigations?