2. FORENSIC SCIENCE INTRODUCTION Crime Scene Investigation

3. 2 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??? 1.Analyze physical evidence 2.Provide Expert Testimony 3.Provide training in the recognition, collection and preservation of physical evidence

4. 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

5. 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 1 st 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 1 st police lab *J. Edgar Hoover: director of the FBI: Organized the 1 st FBI Crime Lab in 1932

6. 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

7. 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!

8. 7 CORPUS DELICTI “Body of the Crime” You must prove : âthat a crime occurred âthat the person charged with the crime was responsible for the crime Top Reasons for Committing a Crime âMoney âRevenge âSex âEmotion--love, hate, anger Source of Evidence âBody âPrimary and/or Secondary Crime Scene âSuspect(s)

9. 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

10. 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-

11. 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…..

12. 11 Crime Scene Team A group of professionals investigators, each trained in a variety of special disciplines. Team Members ãFirst Police Officer on the scene ãMedics (if necessary) ãInvestigator(s) ãMedical Examiner (if necessary) ãPhotographer and/or Field Evidence Technician ãLab Experts pathologistserologist DNA experttoxicologist forensic odontologistforensic anthropologist forensic psychologistforensic entomologist firearm examinerbomb and arson expert document and handwriting expertsfingerprint expert

13. 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

14. 13 First Officer at the Scene ãAAssess the crime scene ãDDetain the witness ãAArrest the perpetrator ãPProtect the crime scene ãTTake notes

15. 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

16. 15 Crime Scene Search Patterns  Spiral  Grid TWO of FOUR PATTERNS

17. 16 Crime Scene Search Patterns  Strip or Line  Quadrant or Zone TWO of FOUR PATTERNS

18. 17 Crime Scene Sketch Date: August 14, 2001Criminalist: Ann Wilson Time: 11:35Location: 4358 Rockledge Dr St. Louis, Mo. A. Couch/sofa B. Female body C. Knife D. Over turned Lamp E. Chairs F. Table G. Fireplace c D E E E E E A G F

19. 18 Crime Scene Mapping (outdoors) âAzimuth--uses a compass beam to determine the location of each piece of evidence âTriangulation--uses two points at the crime scene to map each piece of evidence âCoordinate or grid--divides the crime scene into squares for mapping. âSuspended Polar Coordinate--for use in mapping evidence in a hole âBaseline--set a north/south line and measures each piece of evidence from this line.

20. AZIMUTH Determines: Direction Distance Elevation

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

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

23. 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

24. 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.

25. 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.

26. 25 Physical Evidence Transient Evidence-- temporary; easily changed or lost; usually observed by the first officer at the scene ãOdor--putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke ãTemperature--of room, car hood, coffee, water in a bathtub; cadaver ãImprints and indentations--footprints; teeth marks in perishable foods; tire marks on certain surfaces ãMarkings

27. 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: âBiological âChemical âPhysical âMiscellaneous

28. 27 Biological Evidence âBlood âSemen âSaliva âSweat/Tears âHair âBone âTissues âUrine âFeces âAnimal Material âInsects âBacterial/Fungal

29. 28 Chemical Evidence âFibers âGlass âSoil âGunpowder âMetal âMineral âNarcotics âDrugs âPaper âInk âCosmetics âPaint âPlastic âLubricants âFertilizer

30. 29 Physical (impression) âFingerprints âFootprints âShoe prints âHandwriting âFirearms âPrinting âNumber restoration âTire marks âTool marks âTypewriting

31. 30 Miscellaneous âLaundry marks âVoice analysis âPolygraph âPhotography âStress evaluation âPyscholinguistic analysis âVehicle identification

32. 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. âLight--headlight; lighting conditions âSmoke--color, direction of travel, density, odor âFire--color and direction of the flames, speed of spread, temperature and condition of fire

33. 32 Conditional Evidence (cont.) âLocation--of injuries or wounds; of bloodstains; of the victims vehicle;of weapons or cartridge cases; of broken glass, etc. âVehicles--doors locked or unlocked, windows opened or closed; radio off or on (station); odometer mileage âBody--position; types of wounds; rigor, livor and algor mortis âScene--condition of furniture, doors and windows; any disturbance or signs of a struggle.

34. 33 Evidence Characteristics Class--common to a group of objects or persons Individual--can be identified with a particular person or source. ABO Blood TypingBlood DNA Typing

35. 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.

36. 35 Medical Examiner’s Responsibilities ãIdentify the deceased ãEstablish the time and date of death ãDetermine a medical cause of death -- the injury or disease that resulted in the person dying ãDetermine the mechanism of death -- the physiological reason that the person died ãClassify the manner of death ãNatural ãAccidental ãSuicide ãHomicide ãUndetermined ãNotify the next of kin

37. 36 THE BODY Rigor Mortis Temperature Stiffness Time Since of body of body Death Warm Cold Not stiff Stiff Not stiff Not dead more than 3 hrs Dead between 3 and 8 hrs Dead 8 to 36 hours Dead more than 36 hours

38. 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.

39. 38 THE BODY Algor Mortis Algor mortis is body temperature. Average human body temperature: 98.6 F (37 C)

40. 39 Time Frame of Death â ConditionAppearance â Periphery blood drying30 min to 2 hrs â Blue-green discoloration of skin â Right and left area of abdomen24 hours â Entire abdomen36 hours â Bloating36 to 48 hours â Skin slippage4 to7 days â Absence of smell from bonesmore than 1 year

41. 40 Time Frame of Death Eyeball Changes â ConditionAppearance â Cornea drying (eyes open)minutes â Cornea drying (eyes closed)2 hours â Corneal cloudiness (eyes open)less than 2 hours â Corneal cloudiness (eyes closed) 12 to 24 hours â Eyeball collapsemore than 24 hrs

42. 41 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. THEREFORE,

43. 42 CRIME += What Happened? Why Did It Happened? Who Did It? Crime Scene Evidence Collection Witness, Suspect and Motive Development Post Scene Evidence Processing Cause, manner, time of death Investigative Stage Profiling Means Motive Opportunity Identification and Arrest of Suspect

44. 43 Forensic Investigations Include some or all of these seven major activities ãRecognition--ability to distinguish important evidence from unrelated material ãPattern recognition ãPhysical property observation ãInformation analysis ãField-testing ãPreservation--collection and proper preservation of evidence

45. 44 Investigations (cont) âIdentification--use of scientific testing âPhysical properties âChemical properties âMorphological (structural) properties âBiological properties âImmunological properties âComparison--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.

46. 45 Investigations (cont.) âIndividualization--demonstrating that the sample is unique, even among members of the same class. âInterpretation--gives meaning to all the information âReconstruction--reconstructs the case events âInductive and deductive logic âStatistical data âPattern analysis âResults of laboratory analysis Lee, Dr. Henry. Famous Crimes. Southington:Strong Books, 2001

47. 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?