1 Forensic Science Chapter 1: Introduction

2 Forensic science Applies the knowledge and technology of science for the definition and enforcement of laws Criminal justice Provide accurate and objective information Food safety and quality Medications Water purity Pesticide use Air pollution

3 Limited definition For this class, Forensic science is the application of science to those criminal and civil laws that are enforced by police. We will deal with crime-scene and evidence analysis Not medicine, psychology, etc.

4 Criminalistics Another term for forensic science Specifically applied to crime solving

5 History and development of forensic science Made popular by Sir Arthur Conan Doyle Author of Sherlock Holmes stories Often imagined scientific detection methods before they were actually discovered Predicted ability to identify blood stains with a chemical that reacts only with hemoglobin

6 Mathieu Orfila 1787 – 1853 Father of forensic toxicology 1814 – Studied detection of poisons and their effects on animals

7 Aphonse Bertillon 1853 – – Anthropometry Used series of body measurements for identification Replaced by fingerprinting in early 1900s Still used as part of facial recognition

8 Francis Galton 1822 – – fingerprint analysis and identification

9 Leone Lattes 1887 – – procedure for determining blood group (A, B, AB, or O) of dried bloodstains

10 Calvin Goddard 1891 – 1955 Used comparison microscope to examine bullets from crime scenes and from suspects’ weapons

11 Albert S. Osborn 1858 – – Questioned Documents – document examination procedures Still used as a reference

12 Walter C. McCrone 1916 – 2002 Using microscopes to examine evidence Hairs, fibers, organic material, etc.

13 Hans Gross 1847 – – advocated the application of science to criminal investigations

14 Edmond Locard 1877 – – started police lab in Lyons, France Believed that every criminal can be connected to a crime by dust particles carried from the crime scene Proved this in a series of well-publicized investigations Led to the formation of other police laboratories throughout Europe

15 Locard’s Exchange Principle The exchange of materials between two objects that occurs whenever two objects come into contact with one another.

16 FBI Lab Established in 1932 J. Edgar Hoover Now the world’s largest forensic science lab Model for labs around the US and in other countries Training Center – 1981 – training and research into new forensic science methods

17 LAPD lab Oldest in the US 1923

18 Labs in the US Local and independent Federal State County City California has unified somewhat into a network, exchanging information and expertise

19 Labs in Britain National system of regional labs Police pay a fee for services of labs More efficient? More “fair”?

20 Growth in crime labs Number of labs greatly increases in past 35 years Court decisions favoring scientific evidence Miranda warning Modern technology – DNA Increase in crime rate – especially drugs

21 Federal labs FBI DEA (Drug Enforcement Administration) ATF (Bureau of Alcohol, Tobacco, Firearms, and Explosives) USPS (Postal service)

22 Basic lab services Physical Science Biology Firearms Document Examination Photography

23 Physical Science Chemistry, Physics, Geology Chemicals Trace elements Drug identification

24 Biology DNA Compare hairs and fibers Compare botanicals – wood and plants

25 Firearms Unit Guns Ammunition Gunshot residue Tool marks

26 Document Examination Handwriting and typewriting Paper and ink analysis Indented writings Damaged documents (burned, etc.)

27 Photography Record evidence Digital imaging IR, UV, and X-ray photography Prepare courtroom exhibits

28 Optional lab services Toxicology Fingerprints Polygraph Voiceprint Evidence collection

29 Toxicology Find drugs or poisons in tissues and fluids

30 Fingerprints Processing and examining fingerprints

31 Polygraph Lie detectors Users must be trained in interrogation Not purely scientific – results not always reliable

32 Voiceprint Compare voices on different recordings Individuals produce unique sound and speech patterns

33 Evidence collection Trained personnel to collect evidence from the scene

34 Reality check A criminalist will normally work in only one area – the scene OR the lab If they are in the lab, they usually are in one specific area, they don’t know about everything

35 Analyzing evidence Scientists must be aware of court rulings on procedures and techniques

36 The Frye Standard Named after Frye v. United States (1923) When the lie detector test was rejected The technique in question must be accepted by a meaningful segment of the scientific community Must be “generally accepted”

37 Federal rules of Evidence More flexible Daubert v. Merrell Dow Pharmaceutical, Inc. (1993) The trial judge can act as a “gatekeeper” and determine whether or not the science is based on a reliable foundation Has it been tested? Has it been reviewed and published? What is its rate of error? Are there standard operating procedures? Is it widely accepted?

38 KumhoTire Co., Ltd. V. Carmichael 1999 “gatekeeping” role applies to all expert testimony “technical” “other specialized”

39 Coppolino v. State (Florida) Cause of death was overdose of a drug that had never before been detected in the human body Medical examiner’s explanation satisfied judge, despite lack of other experimental data Allowed testimony “Society need not tolerate homicide until there develops a body of medical literature about some particular lethal agent.”

40 Expert witness An individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person

41 Expert knowledge Can be acquired through Experience Training Education Combination of above

42 Forensic science experts Usually don’t have degrees in forensic science Chemistry Biology Physics Geology Rely on training and years of experience

43 Credibility Expert witnesses must prove their knowledge by citing degrees and experience They may also be asked questions to prove or disprove their expertise

44 Offering opinions Ordinary witnesses must only present facts that come from personal knowledge Expert witnesses may present opinions on the significance of scientific findings Must present only the truth – including possible errors in the methods

45 Evidence collection Specially-trained technicians Police officers must also be trained

46 Forensic Pathology Investigation of sudden, unnatural, unexplained, or violent deaths Autopsy – the medical dissection and examination of a body in order to determine cause of death Natural Homicide Suicide Accident undetermined

47 Rigor Mortis The medical condition that occurs after death and results in the shortening of muscle tissue and the stiffening of body parts in the position they are in when death occurs Appears within 24 hours, gone in 36 hours

48 Livor mortis The medical condition that occurs after death and results in the settling of blood in areas of the body closest to the ground Begins immediately and lasts for up to 12 hours

49 Algor Mortis Postmortem changes that cause a body to lose heat About 1 to 1 ½ degrees F each hour Depends on location and size of body, clothing, and weather conditions

50 Forensic Anthropology Identification and examination of skeletal remains Can reveal sex, age, race, and injuries Facial reconstructions

51 Forensic Entomology Study of insects Used to estimate time of death Depends on temperature

52 Forensic Psychiatry Evaluate behavioral disorders Determine competency Help develop suspect profiles

53 Forensic Odontology Identification through dental records Bite mark analysis

54 Forensic Engineering Failure analysis Accident reconstruction Causes and origins of fires and explosions