Crime Investigation & Forensic Science: Concepts, Tools, and Applications

2. Crime Investigation & Forensic Science ByMuhammad Tariq Chohan

3. Sequence Introduction Definition of crime Investigation – concept and tools Kind of evidence Forensic Science - definition and concept Basic principles of Forensic Science Applications: Anthropometry, dactylography, DNA , blood sampling, document analysis Problems and limitations Conclusion

4. Introduction A

5. Definition of Crime A Crime is the commission or omission of any act, which is prohibited or required by the penal code of an organized political state, to which some punishment or sanction is attached.

6. Classification Crime against person e.g Murder, Attempted Murder, Hurt, threats etc. Crime against property e.gDacoity, Robbery, theft, House breaking, extraction etc. Fraud and forgery e.g fake documents, embezzlement etc. Cyber Crime

7. Crime Investigation Definition:- An investigation is systematic, minute and thorough attempt to learned the facts about some thing complex or hidden Police Investigation - the investigation of criminal activities Investigating, investigation – the work of inquiring into something thoroughly and systematically Detecting, detective work, sleuthing, detection – a police investigation to determine the perpetrator; “ detection is hard on the feet” Forensics – Scientific tests or techniques used in the investigation of crimes Roundup – the systematic gathering up of suspects by the police; “ a mass roundup of suspects” Surveillance – close observation of a person or group ( usually by the police)

8. Investigator • Someone who gathers, documents and evaluates evidence. • Strong professional training and experience • Strong degree of self-discipline • Uses legally approved & ethical methods • Strong people skills • Includes all evidence of innocence as well as guilt • Uses systematic methods of inquiry • Uses both inductive and deductive reasoning • Compassionate, not calloused and cynical • Has wide ranging contacts across many occupations • Remains objective at all times • Leaves nothing to chance during investigation

9. Investigative Process • Objectives • Establish if a crime was committed • Collect, document and preserve evidence • Identify and apprehend the suspect(s) • Recover stolen property • Assist in the prosecution of the person(s) charged with the crime(s)

10. Crime Scene • Location where the offense was committed • May include surrounding areas where evidence may • be located • Always start big . . . It’s much easier to make it smaller • than to expand it at a later time • There may be more than one crime scene • Macroscopic versus Microscopic scenes

11. CONCEPTUALIZATION Keep known fact AND inferences in mind when processing scene • Facilitates reconstruction of the offense • Identification of the modus operandi • Identification of certain types of evidence • Assists in establishing investigative direction

12. Spiral • Strip/Line • Grid • Zone/Quadrant • Pie/Wheel CRIME SCENE SEARCH PATTERNS The crime scene coordinator may choose from a variety of crime scene search patterns based upon the type and size of the crime scene.

13. DOCUMENTATION Constant Activity • Starts with rough shorthand field notes • Sketches • Diagrams to scale • WAYS TO DOCUMENT A CRIME SCENE VISUALLY • INCLUDE: • Video taping • Photographing • Sketching

14. Categories of Evidence • Corpus Delicti evidence • Evidence that helps to prove the elements of the crime(s) • Associative evidence Evidence that connects the suspect to the scene and/or victim or connects the scene/victim to the suspect It is bidirectional • Trace evidence Small or microscopic evidence, or evidence in limited amounts

15. Forensic Science - definition and concept Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action. Forensic Science is concerned with reconstruction of unique events – attempting to determine what happened, how it happened, where and when it happened, and who was involved.

16. Five stages of physical evidence of process Foundation Recovery Analysis Interpretation Presentation

17. Principles of Forensics Science 1.Principles concerning occurrence of evidence Locard principles of exchange: “ Every contact leaves a trace”. The dust and debris that cover our clothing and bodies are the mute witnesses, sure and faithful, of all our movements and all our encounters. The absence of evidence is not necessarily the evidence of absence.

18. Cont…. 2. Principles of evidence recovery First, do no harm Nothing should be added Nothing should be damage Nothing should be lost

19. Cont…. 3. Principles of analysis Scientific method Observation Data collection Conjecture / hypothesis Testing results Theory

20. Cont… 4. Principles of interpretation Principle of individuality. Tow objects may be indistinguishable but no tow objects are identical Principle of comparison: tow objects are said to match ( be indistinguishable) when there are no unexplained, forensically significant differences between them

21. 5- Principles of presentation Working within an ethical framework, a forensic scientist should fully disclose and present impartial evidence which is readily under stanadable and neither overstated nor understated.

22. ANTHROPOMETRY • First method of criminal identification thought to be reliable; based on a criteria of body measurements • Developed by Bertillon (1853-1916)/father of criminal identification • After 1883 the system was adopted throughout Europe • System was abandoned because dactylography (fingerprint identification) simpler, more reliable

23. HENRY BERTILLON AND A BERTILLON MEASUREMENT

24. MILESTONES IN THE DEVELOPMENT OF DACTYLOGRAPHY 1684 England’s Dr. Grew observes pores and ridges in hands and feet 1823 Perkinje develops nine standard fingerprint patterns and classification system 1892 Galton publishes “Fingerprints,” first definitive book on dactylography 1894 Vucetich publishes “DictiloscopiaComparada”, outlining his system

25. MILESTONES IN THE DEVELOPMENTOF DACTYLOGRAPHY (Cont.) 1900 The Henry system was adopted in England 1901 Henry publishes “Classification and Use of Fingerprints,” outlining his system of fingerprint classification 1903 The Will West/William West case demonstrates the superiority of dactylography to anthropometry

26. THREE BROAD CATEGORIES OF LATENT FINGERPRINTS • Plastic prints • Created when the fingers touch against some material such as putty • Contaminated/visible prints • Formed when the fingers are contaminated with such things as ink or blood and touch a clean surface • Latent/invisible prints • Left on a surface from the small amounts of body oil and perspiration that are normally found on friction ridges 3-9(a)

27. CONDITIONS AFFECTING THE QUALITY OF LATENT FINGERPRINTS The surface on which the print is deposited The nature of the material contaminating the fingerprint Any physical or occupational defects of the person making the print How the object on which the prints appear was handled The amount of the contamination 3-10

28. METHODS OF DEVELOPING LATENT PRINTS • Traditional powders • Fluorescent Powders • Chemicals • Cyanoacrylate of superglue fuming • Visualization under: • Laser • Alternative light • Ultraviolet illumination 3-11

29. LOCATING PRINTS Crime Scene Technician • This technician is using powder to develop latent prints • Technicians often wear protective equipment • Several points can be seen (Courtesy Nassau County, New York, Police Department) 3-12

30. PORTABLE SUPERGLUE FUMING CHAMBER is used to process the inside and the outside of the car. is more efficient for processing larger objects.

31. LOCATING AND HANDLING SOIL EVIDENCE • Soil evidence is important when the suspect drives/walks on unpaved areas • It is picked up by: • tire treads • shoe bottoms • pants cuffs • It may also be located in: • subject's vehicle • articles in a suspect's trunk 3-4

32. PRESERVING FOOTWEAR AND TIRE PRINTS AND IMPRESSIONS • Footwear prints and impressions should be photographed: • As part of the general scene • Also photograph with a scale • Dental Stone is used in casting impressions 3-5

33. FOOTWEAR IMPRESSIONS • Photographs of footwear impressions at a crime scene • In the first photo only the impressions are shown • In a subsequent photo a ruler will be added to show sizes • Later casts will be made of the impressions (Courtesy Tampa, Florida, Police Department) 3-6

34. collecting glass and paint evidence Paint may be collected from the suspect's tools or clothing. Paint can often be collected in dried chips. Glass is a common form of evidence at burglary scenes. Before any glass fragments are removed from a glass window it should be photographed. 3-7

35. DNA • Deoxyribonucleic Acid, chemical blueprint which determines everything from our hair color to our disease vulnerabilities; with the exception of identical twins, each person has a unique DNA makeup • DNA is unique to individuals • The human sources of DNA are: blood and tissue; spermatozoa; bone marrow, tooth pulp and hair root cells

36. DNA TYPING • DNA is a chemical blueprint • The Enderby cases were the first use DNA typing in England in 1987 • The Orlando cases were the first used in the U.S. in1986 • The FBI crime lab was the first public lab to use DNA analysis in 1988

37. SOURCES OF DNA EVIDENCE These are common sources of blood and DNA evidence that investigators need to be aware of in conducting crime scene searches.

38. IDENTIFYING AND ANALYZING BLOOD STAINS If blood at the crime scene is fresh and relatively uncontaminated, identification is not difficult If the conditions at a crime scene are otherwise it is more difficult to identify One preliminary field test involves the use of Hemident Blood analyses is important because of the value of DNA typing 3-16

39. HEMIDENT The use of Hemident in a presumptive or preliminary field test for blood. (Courtesy Lightning Powder Company, Salem, Oregon) 3-18

40. FORENSIC DENTISTRY Forensic dentistry is a specialty that relates dental evidence to investigation Analyses of bit marks had played a major role in many cases Teeth marks may be left in food, pencils or other items left at crime scenes Bite marks can help eliminate or identify suspects

41. DENTAL COMPARISON Dental records are very useful in helping to identify unknown persons who have been the victim of fowl play or who have been reported simply missing. (Courtesy Dr. Richard R. Souviron, D.D.S., ABFO, Chief Forensic Odontologist, Dade County Medical Examiner Department, Miami, Florida) 3-15

42. MILESTONES IN FIREARMS IDENTIFICATION 1835 Henry Goddard First successful murderer identification from bullet removed from victim’s body 1889 Professor Lacassagne identified grooves on a removed bullet removed from a corpse and matched it to a suspect’s weapon 1898 Jeserich took microphotographs of fatal and test bullets He testified the defendant’s revolver fired the fatal bullet 1926 Calvin Goddard was most responsible for raising firearm identification to a science

43. BULLET IDENTIFICATION • When a bullet passes through the barrel of a weapon distinctive scratches are caused • These scratches can be compared to bullets fired through firearms in question • Identification is affected by the condition of the gun and of the bullets 3-20

44. TECHNIQUES FOR IDENTIFYING QUESTIONED DOCUMENTS • Handwriting and handprinting examinations • There are three types of forgery: • Traced forgery • Simulated forgery • Freehand forgery 3-22(a)

45. TECHNIQUES FOR IDENTIFYING QUESTIONED DOCUMENTS (cont'd) Photocopier examination Paper examination Age of documents Burned or charred paper Altered or obliterated writing Writing instruments mechanical-impression instruments Typewriting 3-22(b)